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Summary of significant accounting policies | 12 Months Ended
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Dec. 31, 2016
Summary of significant accounting policies |
Summary of significant accounting policies | 2. Summary of significant accounting policies Basis of presentation and consolidation Our consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP"). The accompanying consolidated financial statements include our accounts and the accounts of our majority owned subsidiaries. We consolidate our 70% ownership of Chicago Concourse Development Group, LLC and our 75% ownership of Boingo Holding Participacoes Ltda. in accordance with Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") 810, Consolidation. Other parties' interests in consolidated entities are reported as non-controlling interests. All intercompany balances and transactions have been eliminated in consolidation. Prior to August 4, 2015, we had a 70% ownership of Concourse Communications Detroit, LLC. On August 4, 2015, we purchased the remaining 30% ownership interest from the non-controlling interest owners for $1,150. We accounted for this transaction as an acquisition of the remaining interest of an entity that had already been majority-owned by the Company. The purchase resulted in a reduction to additional paid-in capital of $1,150 representing excess purchase price over the carrying amount of the non-controlling interests. Prior to this purchase, we had a controlling interest in this subsidiary, and therefore, this subsidiary had been and will continue to be consolidated with the Company's operations. In March 2016, the FASB issued Accounting Standards Update ("ASU") 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09"), which simplifies several aspects of the accounting for share-based payments including the following: entities record all excess tax benefits and tax deficiencies as an income tax benefit or expense in the income statement; entities classify excess tax benefits as an operating activity in the statement of cash flows; entities elect an accounting policy to either estimate the number of forfeitures (current U.S. GAAP) or account for forfeitures when they occur; and entities can withhold up to the maximum individual statutory rate without classifying the awards as a liability with the cash paid to satisfy the statutory income tax withholding obligation classified as a financing activity in the statement of cash flows. The standard provides for prospective, retrospective, or modified retrospective adoption of each of the changes, and the standard is effective for public entities for interim and annual periods beginning after December 15, 2016. Early adoption is permitted and we elected to early adopt ASU 2016-09 as of January 1, 2016. As a result of this adoption, we recorded $6,933 and $589 of net deferred tax assets related to our federal and state net operating losses for excess windfall tax benefits, respectively, as of January 1, 2016. We established a full valuation allowance against those deferred tax assets as of January 1, 2016 based on the determination that it was more likely than not that those deferred tax assets would not be realized. We also elected to change our accounting policy to account for forfeitures when they occur on a modified retrospective basis. The change in our accounting policy resulted in a $94 increase to additional paid-in capital and accumulated deficit as of January 1, 2016. In August 2014, the FASB issued ASU 2014-15, Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern, which explicitly requires management to assess an entity's ability to continue as a going concern in connection with each annual and interim period. Management will assess if there is substantial doubt about an entity's ability to continue as a going concern within one year of the date the financial statements are issued. Disclosures will be required if conditions give rise to substantial doubt. The standard will be effective for the first annual period ending after December 15, 2016. Early adoption is permitted. We adopted this standard effective December 31, 2016. This standard did not have a material impact on our consolidated financial statements. Use of estimates The preparation of accompanying consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the dates of the accompanying consolidated financial statements, and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. Assets and liabilities which are subject to significant judgment and the use of estimates include the allowance for doubtful accounts, recoverability of goodwill and long-lived assets, valuation allowances with respect to deferred tax assets, uncertain tax positions, useful lives associated with property and equipment, valuation and useful lives of intangible assets, and the valuation and assumptions underlying stock-based compensation and other equity instruments. On an ongoing basis, we evaluate our estimates compared to historical experience and trends, which form the basis for making judgments about the carrying value of assets and liabilities. Concentrations of credit risk Financial instruments that potentially subject us to significant concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. We maintain our cash and cash equivalents with institutions with high credit ratings. We extend credit based upon the evaluation of the customer's financial condition and generally collateral is not required. We maintain an allowance for doubtful accounts based upon expected collectability of accounts receivable. We primarily estimate our allowance for doubtful accounts based on a specific review of significant outstanding accounts receivable. For the year ended December 31, 2016, two customers accounted for 23% of total revenue. For the years ended December 31, 2015 and 2014, one customer accounted for 17% and 15% of total revenue, respectively. At December 31, 2016, three customers accounted for 26%, 18% and 17% of the total accounts receivable, respectively. At December 31, 2015, four customers accounted for 28%, 19%, 19% and 10% of the total accounts receivable, respectively. Cash and cash equivalents Cash and cash equivalents include highly liquid investments that are readily convertible into known amounts of cash with original maturities of three months or less when acquired. At December 31, 2016 and 2015, cash equivalents consisted of money market funds. Fair value of financial instruments Fair value is defined as the price that would be received from selling an asset, or paid to transfer a liability, in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at fair value, we consider the principal or most advantageous market in which it would transact, and we consider assumptions that market participants would use when pricing the asset or liability. The accounting guidance for fair value measurement also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard establishes a fair value hierarchy based on the level of independent, objective evidence surrounding the inputs used to measure fair value. A financial instrument's categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The fair value hierarchy is as follows:
| • | Level 1—Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.
| • | Level 2—Quoted prices for identical assets and liabilities in markets that are not active, quoted prices for similar assets and liabilities in active markets or financial instruments for which significant inputs are observable, either directly or indirectly.
| • | Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
The carrying amount reflected in the accompanying consolidated balance sheets for cash and cash equivalents, accounts receivable, prepaid expenses and other current assets, other assets, accounts payable, accrued expenses and other liabilities, and deferred revenue approximates fair value due to the short duration and nature of these financial instruments. Property and equipment Property and equipment are generally stated at historical cost, less accumulated depreciation and amortization. The Company's cost basis includes property and equipment acquired in business combinations that were initially recorded at fair value as of the date of acquisition. Maintenance and repairs are charged to expense as incurred and the cost of additions and betterments that increase the useful lives of the assets are capitalized. Depreciation and amortization is computed over the estimated useful lives of the related asset type using the straight-line method. The estimated useful lives for property and equipment are as follows:
Software |  | 2 to 5 years
Computer equipment |  | 3 to 5 years
Furniture, fixtures and office equipment |  | 3 to 5 years
Leasehold improvements |  | The shorter of the estimated useful life or the remaining term of the agreements, generally ranging from 2 to 18 years
Leasehold improvements are principally comprised of network equipment located at various managed and operated locations, primarily airports, under exclusive, long-term, non-cancelable contracts to provide wireless communication network access. We capitalize certain costs for our network equipment during the pre-construction period, which is the period during which costs are incurred to evaluate the site, and continue to capitalize costs until the network equipment is substantially completed and ready for use. Cost for network equipment includes capitalized interest. Equipment and software under capital lease We lease certain data communications equipment, other equipment and software under capital lease agreements. The assets and liabilities under capital lease are recorded at the lesser of the present value of aggregate future minimum lease payments, including estimated bargain purchase options, or the fair value of the asset under lease. Assets under capital lease are depreciated using the straight-line method over the estimated useful lives of the assets or the term of the lease agreements. Software development costs We capitalize costs associated with software developed or obtained for internal use when the preliminary project stage is completed and it is determined that the software will provide significantly enhanced capabilities and modifications. These capitalized costs are included in property and equipment and include external direct cost of services procured in developing or obtaining internal-use software and personnel and related expenses for employees who are directly associated with, and who devote time to internal-use software projects. Capitalization of these costs ceases once the project is substantially complete and the software is ready for its intended use. Once the software is ready for its intended use, the costs are amortized over the useful life of the software. Post-configuration training and maintenance costs are expensed as incurred. Long-lived assets Intangible assets consist of acquired venue contracts, technology, advertiser relationships, non-compete agreements and patents and trademarks. We record intangible assets at fair value as of the date of acquisition and amortize these finite-lived assets over the shorter of the contractual life or the estimated useful life on a straight-line basis. We estimate the useful lives of acquired intangible assets based on factors that include the planned use of each acquired intangible asset, the expected pattern of future cash flows to be derived from each acquired intangible asset and contractual periods specified in the related agreements. As such, we account for each of the venue contracts individually. We include amortization of acquired intangibles in amortization of intangible assets in the accompanying consolidated statements of operations. We perform an impairment review of long-lived assets held and used whenever events or changes in circumstances indicate that the carrying value may not be recoverable. Factors we consider important that could trigger an impairment review include, but are not limited to: significant under-performance relative to projected future operating results, significant changes in the manner of our use of the acquired assets or our overall business and product strategies and significant industry or economic trends. When we determine that the carrying value of a long-lived asset may not be recoverable based upon the existence of one or more of these indicators, we determine the recoverability by comparing the carrying amount of the asset to net future undiscounted cash flows that the asset is expected to generate or other indices of fair value. We would then recognize an impairment charge equal to the amount by which the carrying amount exceeds the fair market value of the asset. Goodwill Goodwill represents the excess of the purchase price over the fair value of net assets acquired in connection with the acquisition of Concourse Communication Group, LLC in June 2006, Cloud 9 Wireless, Inc. in August 2012, Endeka Group, Inc. in February 2013, and Electronic Media Systems, Inc. and Advanced Wireless Group, LLC in October 2013. We test goodwill for impairment in accordance with guidance provided by FASB ASC 350, Intangibles—Goodwill and Other ("ASC 350"). Goodwill is tested for impairment at least annually at the reporting unit level or whenever events or changes in circumstances indicate that goodwill might be impaired. Events or changes in circumstances which could trigger an impairment review include a significant adverse change in legal factors or in the business climate, an adverse action or assessment by a regulator, unanticipated competition, a loss of key personnel, significant changes in the manner of our use of the acquired assets or the strategy for our overall business, significant negative industry or economic trends, or significant underperformance relative to expected historical or projected future results of operations. We perform our impairment test annually as of December 31st. Entities have the option to first assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test described in FASB ASC 350. If, after assessing qualitative factors, an entity determines it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing the two-step impairment test is unnecessary. If deemed necessary, a two-step test is used to identify the potential impairment and to measure the amount of goodwill impairment, if any. The first step is to compare the fair value of the reporting unit with its carrying amount, including goodwill. If the fair value of the reporting unit exceeds its carrying amount, goodwill is considered not impaired; otherwise, there is an indication that goodwill may be impaired and the amount of the loss, if any, is measured by performing step two. Under step two, the impairment loss, if any, is measured by comparing the implied fair value of the reporting unit goodwill with the carrying amount of goodwill. Currently, we have one reporting unit, one operating segment and one reportable segment. At December 31, 2016 and 2015, all of the goodwill was attributed to our reporting unit. We tested our goodwill for impairment using a market based approach and no impairment was identified as the fair value of our reporting unit was substantially in excess of its carrying amount. To date, we have not recorded any goodwill impairment charges. Revenue recognition We generate revenue from several sources including: (i) DAS customers that are telecom operators under long-term contracts for access to our DAS at our managed and operated locations, (ii) military and retail customers under subscription plans for month-to-month network access that automatically renew, and military and retail single-use access from sales of hourly, daily or other single-use access plans, (iii) arrangements with wholesale Wi-Fi customers that provide software licensing, network access, and/or professional services fees, and (iv) display advertisements and sponsorships on our walled garden sign-in pages. Software licensed by our wholesale platform services customers can only be used during the term of the service arrangements and has no utility to them upon termination of the service arrangement. We recognize revenue when an arrangement exists, services have been rendered, fees are fixed or determinable, no significant obligations remain related to the earned fees and collection of the related receivable is reasonably assured. Revenue is presented net of any sales and value added taxes. Revenue generated from access to our DAS networks consists of build-out fees and recurring access fees under certain long-term contracts with telecom operators. Build-out fees paid upfront are generally deferred and recognized ratably over the term of the estimated customer relationship period, once the build-out is complete. Periodically, we install and sell Wi-Fi and DAS networks to customers where we do not have service contracts or remaining obligations beyond the installation of those networks and we recognize build-out fees for such projects as revenue when the installation work is completed and the network has been accepted by the customer. Minimum monthly access fees for usage of the DAS networks are non-cancellable and generally escalate on an annual basis. These minimum monthly access fees are recognized ratably over the term of the telecom operator agreement. The initial term of our contracts with telecom operators generally range from five to twenty years and the agreements generally contain renewal clauses. Revenue from DAS network access fees in excess of the monthly minimums is recognized when earned. Subscription fees from military and retail customers are paid monthly in advance and revenue is deferred for the portions of monthly recurring subscription fees collected in advance. We provide refunds for our military and retail services on a case-by-case basis. These amounts are not significant and are recorded as contra-revenue in the period the refunds are made. Subscription fee revenue is recognized ratably over the subscription period. Revenue generated from military and retail single-use access is recognized when access is provided. Services provided to wholesale Wi-Fi partners generally contain several elements including: (i) a term license to use our software to access our Wi-Fi network, (ii) access fees for Wi-Fi network usage, and/or (iii) professional services for software integration and customization and to maintain the Wi-Fi service. The term license, monthly minimum network access fees and professional services are billed on a monthly basis based upon predetermined fixed rates. Once the term license for integration and customization are delivered, the fees from the arrangement are recognized ratably over the remaining term of the service arrangement. The initial term of the license agreements is generally between one to five years and the agreements generally contain renewal clauses. Revenue for Wi-Fi network access fees in excess of the monthly minimum amounts is recognized when earned. All elements within existing service arrangements are generally delivered and earned concurrently throughout the term of the respective service arrangement. In instances where the minimum monthly Wi-Fi and DAS network access fees escalate over the term of the wholesale service arrangement, an unbilled receivable is recognized when performance is within our control and when we have reasonable assurance that the unbilled receivable balance will be collected. We adopted the provisions of ASU 2009-13, Revenue Recognition (Topic 605)—Multiple-Deliverable Revenue Arrangements ("ASU 2009-13"), on a prospective basis on January 1, 2011. For multiple-deliverable arrangements entered into prior to January 1, 2011 that are accounted for under ASC 605-25, Revenue Recognition—Multiple-Deliverable Revenue Arrangements, we defer recognition of revenue for the full arrangement and recognize all revenue ratably over the wholesale service period for Wi-Fi platform service arrangements and the term of the estimated customer relationship period for DAS arrangements, as we do not have evidence of fair value for the undelivered elements in the arrangement. For multiple-deliverable arrangements entered into or materially modified after January 1, 2011 that are accounted for under ASC 605-25, we evaluate whether or not separate units of accounting exist and then allocate the arrangement consideration to all units of accounting based on the relative selling price method using estimated selling prices if vendor specific objective evidence and third party evidence is not available. We recognize the revenue associated with the separate units of accounting upon completion of such services or ratably over the wholesale service period for Wi-Fi platform service arrangements and the term of the estimated customer relationship period for DAS arrangements. Advertising revenue is generated from advertisements on our managed and operated or partner networks. In determining whether an arrangement exists, we ensure that a binding arrangement is in place, such as a standard insertion order or a fully executed customer-specific agreement. Obligations pursuant to our advertising revenue arrangements typically include a minimum number of units or the satisfaction of certain performance criteria. Advertising and other revenue is recognized when the services are performed. Foreign currency translation Our Brazilian subsidiary uses the Brazilian Real as its functional currency. Assets and liabilities of our Brazilian subsidiary are translated to U.S. dollars at period-end rates of exchange, and revenues and expenses are translated at average exchange rates prevailing for each month. The resulting translation adjustments are made directly to a separate component of other comprehensive loss, which is reflected in stockholders' equity in our consolidated balance sheets. As of December 31, 2016 and December 31, 2015, the Company had $(870) and $(1,160), respectively, of cumulative foreign currency translation adjustments, net of tax, which was $0 as of December 31, 2016 and December 31, 2015 due to the full valuation allowance established against our deferred tax assets, in accumulated other comprehensive loss. Some of our subsidiaries also enter into transactions and have monetary assets and liabilities that are denominated in a currency other than the entities' respective functional currencies. Gains and losses from the revaluation of foreign currency transactions and monetary assets and liabilities are included in the consolidated statements of operations. Network access Network access costs consist primarily of revenue share payments to venue owners where our managed and operated hotspots are located, usage-based fees to our roaming network partners for access to their networks, depreciation of equipment related to network build-out projects in our managed and operated locations, and bandwidth and other Internet connectivity expenses in our managed and operated locations. Advertising, marketing and promotion costs Advertising production costs are expensed the first time the advertisement is run. No advertising production costs were capitalized for the years ended December 31, 2016, 2015 and 2014. All other costs of advertising, marketing and promotion are expensed as incurred. Advertising expenses charged to operations totaled $1,925, $1,703 and $1,350 for the years ended December 31, 2016, 2015 and 2014, respectively. Stock-based compensation Our stock-based compensation consists of stock options, and restricted stock units ("RSU") granted to employees and non-employees. We have shifted our stock-based compensation from stock options to RSUs and no stock options were granted in 2016 and 2015. We recognize stock-based compensation expense in accordance with guidance provided by FASB ASC 718, Compensation—Stock Compensation ("ASC 718"). We measure employee stock-based compensation cost at grant date, based on the estimated fair value of the award and recognize the cost on a straight-line basis, net of forfeitures, over the employee requisite service period. We estimate the fair value of stock options using a Black-Scholes option pricing model. The model requires input of assumptions regarding expected term, expected volatility, dividend yield, and a risk-free interest rate. The weighted average assumptions that were used to calculate the grant date fair value of our employee stock option grants are as follows:
|  | 2014 |
Expected term (years) |  |  | 6.25 |
Expected volatility |  |  | 48.6 | %
Risk-free interest rate |  |  | 1.8 | %
Dividend yield |  |  | 0 | %
The expected term of employee stock options represents the weighted-average period that the stock options are expected to remain outstanding. In estimating the expected term for options granted to employees, we applied the simplified method from the Security Exchange Commission ("SEC") Staff Accounting Bulletin ("SAB") Topic 14, Share-Based Payment ("SAB Topic 14"), where options are granted at-the-money. Where options were not granted at-the-money, the expected term of employee stock options represents the weighted-average period that the stock options are expected to remain outstanding and is calculated based upon actual historical exercise and post-vesting cancellations, adjusted for expected future exercise behavior. We determined the fair value of common stock underlying the stock option awards by reference to third party sales of our common stock. We determined the expected volatility assumption using the frequency of daily historical prices of comparable public companies' common stock for a period equal to the expected term of the options in accordance with guidance in ASC 718 and SAB Topic 14. We will continue to monitor peer companies and other relevant factors, including our volatility after there is enough history, used to measure expected volatility for future stock option grants. The risk-free interest rate assumption is based upon observed interest rates on the United States government securities appropriate for the expected term of our employee stock options. The dividend yield assumption is based on our history and expectation of dividend payouts for which no cash dividends have been declared or paid on our common stock, and for which none are anticipated in the foreseeable future. As stock-based compensation expense recognized in our accompanying consolidated statements of operations is based on awards ultimately expected to vest, the amount has been reduced for forfeitures. We early adopted the provisions of ASU 2016-09 on January 1, 2016 and elected to change our accounting policy to account for forfeitures when they occur on a modified retrospective basis. Prior to January 1, 2016, ASC 718 required forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Forfeitures were estimated based on our historical experience and future expectations. Compensation expense for non-employee stock-based awards is recognized in accordance with ASC 718 and FASB ASC 505, Equity. Stock option awards issued to non-employees are accounted for at fair value using the Black-Scholes option pricing model. Management believes that the fair value of the stock options is more reliably measured than the fair value of the services received. We record compensation expense based on the then-current fair value of the stock options at each financial reporting date. Compensation recorded during the service period is adjusted in subsequent periods for changes in the stock options' fair value until the earlier of the date at which the non-employee's performance is complete or a performance commitment is reached, which is generally when the stock award vests. Income taxes We account for income taxes in accordance with FASB ASC 740, Accounting for Income Taxes ("ASC 740"), which requires the recognition of deferred tax assets and liabilities for the future consequences of events that have been recognized in our accompanying consolidated financial statements or tax returns. The measurement of the deferred items is based on enacted tax laws. In the event the future consequences of differences between financial reporting bases and the tax bases of our assets and liabilities result in a deferred tax asset, ASC 740 requires an evaluation of the probability of being able to realize the future benefits indicated by such asset. A valuation allowance related to a deferred tax asset is recorded when it is more likely than not that some portion or the entire deferred tax asset will not be realized. As part of the process of preparing our accompanying consolidated financial statements, we are required to estimate our income taxes in each of the jurisdictions in which we operate. We also assess temporary differences resulting from differing treatment of items, such as deferred revenue, for tax and accounting differences. We record a valuation allowance to reduce the deferred tax assets to the amount of future tax benefit that is more likely than not to be realized. ASC 740 prescribes a recognition threshold and measurement methodology to recognize and measure an income tax position taken, or expected to be taken, in a tax return. The evaluation of a tax position is based on a two-step approach. The first step requires an entity to evaluate whether the tax position would "more likely than not" be sustained upon examination by the appropriate taxing authority. The second step requires the tax position be measured at the largest amount of tax benefit that is greater than 50% likely of being realized upon ultimate settlement. In addition, previously recognized benefits from tax positions that no longer meet the new criteria would no longer be recognized. Changes in recognition or measurement are reflected in the period in which the change occurs. Non-controlling interests Non-controlling interests are comprised of minority holdings in Chicago Concourse Development Group, LLC ("CCDG") and Boingo Holding Participacoes Ltda ("BHPL"). Under the terms of the LLC agreement for CCDG, we are generally required to distribute annually to the CCDG non-controlling interest holders 30% of allocated net profits less capital expenditures of the preceding year. For the years ended December 31, 2016, 2015 and 2014, we made distributions of $286, $500 and $623, respectively, to non-controlling interest holders of CCDG. Under the terms of the LLC agreement for BHPL, we attributed profits and losses to the non-controlling interest in BHPL in proportion to their holdings. For the years ended December 31, 2016, 2015 and 2014, we made no distributions to the non-controlling interest holder of BHPL. Prior to August 4, 2015, we had a 70% ownership of Concourse Communications Detroit, LLC ("CCG Detroit"). On August 4, 2015, we purchased the remaining 30% ownership interest from the non-controlling interest owners for $1,150. We accounted for this transaction as an acquisition of the remaining interest of an entity that had already been majority-owned by the Company. The purchase resulted in a reduction to additional paid-in capital of $1,150 representing excess purchase price over the carrying amount of the non-controlling interests. Under the terms of the limited liability company ("LLC") agreement for CCG Detroit ("Detroit Operating Agreement") profits and losses were allocated to the controlling and non-controlling owners based on specified terms in the Detroit Operating Agreement, which reflected the relative risk and reward of each owner. The profit and loss allocation in the Detroit Operating Agreement specified that the non-controlling owners' allocated profits were limited to the fixed distribution amounts and losses were limited to the non-controlling owners capital account balance with losses in excess of their capital account being fully allocated to the controlling common unit holder. There was no specified term in the Detroit Operating Agreement, but the term of the annual fixed distribution obligation to the non-controlling owner was the same as the term of the venue agreement between CCG Detroit and Detroit Metropolitan Wayne County Airport—which had a seven year initial term with options to extend for an additional four years. We allocated profits and losses in CCG Detroit based on the attribution in the Detroit Operating Agreement. CCG Detroit had generated losses, which reduced the non-controlling owners capital account to zero in 2009 resulting in an allocation to the controlling interest holder all operating losses and deficits created by the annual fixed distributions to the non-controlling interest holder. The fixed distributions were terminated during September 2013 concurrent with the termination of CCG Detroit's agreement with Detroit Metropolitan Wayne County Airport. Net loss per share attributable to common stockholders Basic net loss per share attributable to common stockholders is calculated by dividing loss attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period. Diluted net loss per share attributable to common stockholders adjusts the basic weighted average number of shares of common stock outstanding for the potential dilution that could occur if stock options and RSUs were exercised or converted into common stock. Our common stockholders are not entitled to receive any dividends. Segment and geographic information We operate as one reportable segment; a service provider of wireless connectivity solutions across our managed and operated network and aggregated network for mobile devices such as laptops, smartphones, tablets and other wireless-enabled consumer devices. This single segment is consistent with the internal organization structure and the manner in which operations are reviewed and managed by our Chief Executive Officer, the chief operating decision maker. All significant long-lived tangible assets are held in the United States of America. We do not disclose sales by geographic area because to do so would be impracticable. The following is a summary of our revenue by primary revenue source:
|  | Year Ended December 31, |
|  | 2016 |  | 2015 |  | 2014 |
Revenue: |  |  |  |  |  |  |  |  |  |
DAS |  | $ | 58,182 |  | $ | 46,455 |  | $ | 38,259 |
Military |  |  | 39,975 |  |  | 19,898 |  |  | 4,486 |
Retail |  |  | 26,636 |  |  | 31,763 |  |  | 40,336 |
Wholesale—Wi-Fi |  |  | 22,221 |  |  | 21,923 |  |  | 15,209 |
Advertising and other |  |  | 12,330 |  |  | 19,587 |  |  | 21,007 |
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Total revenue |  | $ | 159,344 |  | $ | 139,626 |  | $ | 119,297 |
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
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Recent accounting pronouncements In January 2017, the FASB issued ASU 2017-04, Intangibles-Goodwill and Other (Topic 350), which simplifies how an entity is required to test goodwill for impairment. An entity will no longer perform a hypothetical purchase price allocation to measure goodwill impairment. Instead, impairment will be measured using the difference between the carrying amount and the fair value of the reporting unit. The standard is effective for interim and annual periods beginning after December 15, 2019 with early adoption permitted for goodwill impairment tests with measurement dates after January 1, 2017. We do not expect that this standard will have a material impact on our consolidated financial statements. In January 2017, the FASB issued ASU 2017-01, Clarifying the Definition of a Business, which provides a new framework for determining whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The standard is effective for interim and annual periods beginning after December 15, 2017 with early adoption permitted. We do not expect that this standard will have a material impact on our consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230), which adds or clarifies guidance to reduce diversity in how certain transactions are classified in the statement of cash flows. The standard is effective for interim and annual periods beginning after December 15, 2017 with early adoption permitted. The standard requires application using a retrospective transition method. We do not expect that this standard will have a material impact on our consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), which requires lessees to recognize assets and liabilities for all leases with lease terms of more than 12 months on the balance sheet. Under the new guidance, the recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee will depend on its classification as a finance or operating lease. The standard is effective for interim and annual periods beginning after December 15, 2018. Early adoption is permitted for all entities on a modified retrospective basis, with elective reliefs. We are currently evaluating the expected impact of this new standard. In May 2014, the FASB issued ASU 2014-09, Revenue From Contracts with Customers, which is intended to improve and converge the financial reporting requirements for revenue from contracts with customers between U.S. GAAP and International Accounting Standards. In accordance with this new standard, an entity would recognize revenue to depict the transfer of promised goods or services. The standard establishes a five-step model and related application guidance, which will replace most existing revenue recognition guidance in U.S. GAAP. The FASB has subsequently issued several updates and proposals to clarify guidance to be applied. In August 2015, the FASB issued ASU 2015-14, Revenue From Contracts with Customers (Topic (606): Deferral of the Effective Date, to defer the effective date of the new revenue standard by one year. In March 2016, the FASB issued ASU 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net), which amends the principal versus agent guidance in the new revenue standard. ASU 2016-08 clarifies that the analysis must focus on whether the entity has control of the goods or services before they are transferred to the customer. In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing, which amends the revenue guidance on identifying performance obligations and accounting for licenses of intellectual property. In May 2016, the FASB issued ASU 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients, which amends certain aspects of Topic 606. In December 2016, the FASB issued ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers, which provides disclosure relief and clarifies the scope and application of the new revenue standard and related cost guidance. The standard, as amended, will be effective for annual and interim periods in fiscal years beginning after December 15, 2017. The FASB also agreed to allow entities to choose to adopt the new standard as of the original effective date. An entity may choose to adopt the new standard either retrospectively or through a cumulative effect adjustment as of the start of the first period for which it applies the new standard. We have selected January 1, 2018 as our effective date but we have not yet selected a transition method. We are currently evaluating the adoption approach. Our final determination will depend on a number of factors, such as the significance of the impact of the new standard on our financial results, our ability to accumulate and analyze the information necessary to assess the impact on prior period financial statements and our ability to maintain two sets of financials under current and new standards if we were to adopt the full retrospective approach. We are in the initial stages of our evaluation of the impact of the new standard on our accounting policies, processes, and system requirements. We have assigned internal resources in addition to the engagement of third party service providers to assist in the evaluation. While we continue to assess all potential impacts under the new standard, there is the potential for significant impacts to the timing of recognition of revenue.

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- Definition The entire disclosure for the general note to the financial statements for the reporting entity which may include, descriptions of the basis of presentation, business description, significant accounting policies, consolidations, reclassifications, new pronouncements not yet adopted and changes in accounting principles. + References No definition available. + Details
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