Goodwill represents the excess of the purchase price in a business combination over the fair value of net tangible and intangible assets acquired. As disclosed in Note 2, Goodwill is tested for impairment at least annually as of October 1st. The changes in the carrying amount of goodwill for the years ended December 31, 2024 and 2023 were as follows (in thousands):

There was no goodwill impairment for the years ended December 31, 2024, 2023 and 2022.

Intangible assets are initially recorded at their acquisition cost, or fair value if acquired as part of a business combination and amortized over their estimated useful lives. Intangible assets consist of a website domain, customer relationships and trade names acquired as part of a business combination, and licensed data acquired by entering into research collaboration agreements. In each license arrangement, the other party provides the Company with specified data, which currently is used primarily for research and development purposes but may also be licensed to third parties. The asset represents the Company’s right to use these datasets. The Company also recognizes a liability for the associated minimum payments that are presented within accrued data licensing fees.

During the years ended December 31, 2024, 2023 and 2022, the Company recorded $0.7 million, $3.8 million and $2.1 million, respectively, in licensed data related to de-identified data obtained through various agreements.

In January 2023, the Company amended a data licensing agreement, which reduced the future data license payments the Company owes in exchange for waiving exclusivity rights on the licensed data. The Company remeasured the related licensed data intangible asset to fair value, which resulted in an impairment of $7.4 million recorded in Research and development during the year ended December 31, 2023. A $7.9 million gain resulting from the related reduction of future data license payments was also recorded in Research and development during the year ended December 31, 2023. The impairment resulted in a reduction of $40.1 million and $32.7 million to gross intangible assets and accumulated amortization, respectively. There were no impairment charges recognized related to intangible assets during the year ended December 31, 2024.

Amortization of intangible assets is recognized using the straight-line method over their estimated useful lives, which range from three to seven years. Amortization expense was $10.9 million, $11.9 million and $13.3 million for the years ended December 31, 2024, 2023 and 2022, respectively, and is recorded in cost of revenues, research and development, or selling, general and administrative expense, depending on use of the asset. The weighted average life of the Company’s intangibles is approximately six years.