Goodwill and Acquired Intangible Assets, Net

12 Months Ended

Dec. 31, 2019

The changes in the carrying amounts of goodwill was as follows (in thousands):


At January 1, 2017	$	9,725
Additions from acquisitions	149,041
At December 31, 2017	158,766
Additions from acquisitions	11,023
Measurement period and other adjustments	771
At December 31, 2018	$	170,560

The carrying amount of goodwill was $170.6 million as of December 31, 2018 and 2019.

Acquired intangible assets consisted of the following as of the dates indicated (in thousands):


	December 31, 2018
	Cost		Accumulated Amortization		Net Book Value		Weighted- average remaining useful life (years)
Developed technology	$	19,096	$	18,628	$	468	0.8
Customer relationships	74,484		14,979		59,505		6.2
Tradenames	1,600		1,600		—
Acquired intangible assets, net	$	95,180	$	35,207	$	59,973


	December 31, 2019
	Cost		Accumulated Amortization		Net Book Value		Weighted- average remaining useful life (years)
Developed technology	$	19,096	$	19,062	$	34	0.2
Customer relationships	74,484		25,360		49,124		5.2
Tradenames	1,600		1,600		—
Acquired intangible assets, net	$	95,180	$	46,022	$	49,158

The Company recorded amortization expense related to acquired intangible assets as follows (in thousands):


	Year Ended December 31,
	2019		2018		2017
Cost of net revenue	$	434	$	11,834	$	5,083
Sales, marketing and support	10,381		10,236		4,570
General and administrative	—		1,098		590
Total amortization of acquired intangible assets	$	10,815	$	23,168	$	10,243

As of December 31, 2019, the total expected future amortization expense of acquired intangible assets by year is as follows (in thousands):


2020	$	10,443
2021	10,197
2022	8,202
2023	7,709
Thereafter	12,607
Total expected future amortization expense	$	49,158