8. Intangible assets, net

Intangible assets other than goodwill consist of the following:


(In thousands)	Weighted average amortization period		December 31, 2015			December 31, 2014
Gross amount:
Purchased IP and capitalized litigation costs		10 years	$	1,659		$	461
Software developed for internal use		3-10 years		2,571			341
Developed technology		5 years		10,716			—
Customer relationship		7 years		30,875			—
Trademarks		20 years		16,357			—
Domain names		20 years		191			—
Database		10 years		25,052			—
Non-competition agreements		5 years		728			—

				88,149			802

Accumulated amortization:
Purchased IP and capitalized litigation costs				(34	)		—
Software developed for internal use				(50	)		(6	)
Developed technology				(133	)		—
Customer relationship				(272	)		—
Trademarks				(50	)		—
Domain names				(1	)		—
Database				(155	)		—
Non-competition agreements				(9	)		—

				(704	)		(6	)

Net intangible assets:
Purchased IP and capitalized litigation costs				1,625			461
Software developed for internal use				2,521			335
Developed technology				10,583			—
Customer relationship				30,603			—
Trademarks				16,307			—
Domain names				190			—
Database				24,897			—
Non-competition agreements				719			—

			$	87,445		$	796

The amount associated with Purchased IP and capitalized litigation costs is mainly related to the intellectual property purchased by TBO from Ole Poulsen (“Purchased IP”) pursuant to the Intellectual Property Purchase Agreement dated October 14, 2014 (“IP Agreement”) and related legal and other costs incurred in defending the Company’s claims to the Purchased IP. The gross amount associated with software developed for internal use mainly represent capitalized costs of internally developed software. The amounts of developed technology, customer relationship, trademarks, domain names, database, and non-competition agreements all represent the fair values of intangible assets acquired as a result of the Fluent Acquisition.

Amortization expenses of $698 and $6 were included in depreciation and amortization expenses for the years ended December 31, 2015 and 2014, respectively. As of December 31, 2015, there were intangible assets of $1,384 and $2,090, included into the gross amounts of Purchased IP and capitalized litigation costs, and software developed for internal use, respectively, that have not started amortization, which would start to amortize when they are put into use.

The Company capitalized $3,428 during the year ended December 31, 2015, with $1,198 related to purchased intellectual property litigation costs and $2,230 related to internally developed software.

Estimated amortization expenses related to the Company’s intangible assets for 2016 through 2020 and thereafter are $10,282, $10,455, $10,455, $10,455, $10,265 and $35,533, respectively.