The following sections and tables provide details of selected balance sheet items (in thousands):

	As of
	October 31, 2019		January 31, 2019
Finished goods	$	6,523	$	7,567
Raw materials		2,961		2,550
Total inventory	$	9,484	$	10,117

	As of
	October 31, 2019		January 31, 2019
Prepaid expenses	$	2,281	$	2,681
Deferred sales commissions, current		2,146		1,081
Convertible note receivable ⁽¹⁾		1,417		—
Deferred inventory costs		802		334
Other current assets		1,836		1,354
Total other current assets	$	8,482	$	5,450

Deferred sales commissions, non-current	$	6,351	$	3,387
Convertible note receivable ⁽¹⁾		—		1,315
Other non-current assets		1,188		677
Total other non-current assets	$	7,539	$	5,379

⁽¹⁾Convertible note receivable from Global Telecomm Corporation was reclassified from non-current assets to current assets as of July 31, 2019.

Customer Acquisition Costs. The Company capitalizes a significant portion of its sales commission costs as an incremental cost of obtaining customer contracts and amortizes to sales and marketing expense over an expected benefit period of five years. Amortization expense for deferred sales commissions was $0.6 million and $0.2 million for the three months ended October 31, 2019 and 2018, respectively, and $1.4 million and $0.4 million for the nine months ended October 31, 2019 and 2018, respectively. To date, there have been no impairment losses related to the costs capitalized.

Global Telecomm Corporation (“GTC”). In December 2018, the Company invested $1.3 million in cash to Global Telecomm Corporation, a small privately-held technology company, in exchange for an 18-month convertible promissory note, bearing interest at 10% annually, that will convert to shares of GTC common or preferred stock upon the occurrence of certain future events. The Company has partnered with GTC on certain research and development and inventory procurement activities. GTC is considered a variable interest entity (“VIE”) for accounting purposes. However, the Company is not required to consolidate GTC into its financial statements because the Company is not the primary beneficiary. As of October 31, 2019 and January 31, 2019, the Company’s maximum exposure to loss was equal to the carrying value of its convertible note receivable, including accrued interest. For all periods presented, the Company held no other variable interests in VIEs.

As a result of the Company’s investment, GTC is a related party of Ooma. During the three and nine months ended October 31, 2019, the Company procured certain raw material inventories from GTC that amounted to approximately $0.5 million and $0.9 million, respectively. As of October 31, 2019 and January 31, 2019, the Company recorded prepaid inventory deposits to GTC of $0.5 million and zero, respectively, included in other current assets on the condensed consolidated balance sheet. As of October 31, 2019 and January 31, 2019, the Company’s non-cancelable purchase commitments with GTC were $2.2 million and zero, respectively.

	As of
	October 31, 2019		January 31, 2019
Payroll and related expenses	$	8,259	$	7,926
Regulatory fees and taxes		4,510		5,645
Short-term operating lease liabilities ⁽¹⁾		1,629		—
Customer sales incentives		1,507		970
Other		5,811		4,507
Total accrued expenses	$	21,716	$	19,048

⁽¹⁾The Company adopted Topic 842, the new accounting standard for leasing arrangements on February 1, 2019. See Note 6: Operating Leases below.