Long-term use of the mark in commerce is one relevant factor to consider in determining whether a mark has acquired distinctiveness. See, e.g., In re La. Fish Fry Prods., Ltd., 797 F.3d 1332, 1336-37 (Fed. Cir. 2015) (holding evidence of long use insufficient to establish acquired distinctiveness of FISH FRY PRODUCTS where evidence involved uses of LOUISIANA FISH FRY PRODUCTS); In re Audemars Piguet Holding SA, Ser. No. 90045780, 2025 TTAB LEXIS 1, at *43-49, *57 n.97 (2025) (holding evidence of applicant’s more than 50 years use of watch trade dress insufficient to establish its aquired distinctiveness where the evidence did not show the precise combination of the multiple design elements and applicant lacked substantial exclusivity); In re Palacio Del Rio, Inc., 2023 USPQ2d 630, at *5-8, *12-13 (TTAB 2023) (holding evidence of applicant’s nearly 55-years use of modular building trade dress for hotel services insufficient to establish its acquired distinctivenss where the examining attorney’s evidence showed the trade dress was "based on design elements that are common to hotel building designs in general"); In re Uman Diagnostics AB, Ser. No. 88960633, 2023 TTAB LEXIS 77, at *51-53 (2023) (holding applicant’s claim of use since at least as early as November 13, 2012 insufficient to show the mark NF-LIGHT had become distinctive because the mark was highly descriptive and the record showed applicant’s use had not been substantially exclusive in the relevant industry); In re Guaranteed Rate, Inc., Ser. No. 87054820, 2020 TTAB LEXIS 265, at *22-23 (2020) (finding Trademark Act §2(f) claim based on applicant’s use since 2000 not dispositive, even if the use was considered "substantially exclusive," due to the highly descriptive nature of applicant’s mark and the nature and number of third-party descriptive uses in the record); In re OEP Enters., Inc., Ser. No. 87345596, 2019 TTAB LEXIS 278, at *67-68 (2019) (finding applicant’s evidence of use since 1998 of an umbrella trade dress design "supports a finding of acquired distinctiveness to some extent because there is no evidence that competitive double canopy umbrellas had a mesh design between 1998 and 2017"); In re Hikari Sales USA, Inc., Ser. No. 86439012, 2019 TTAB LEXIS 73, at *58-59 (2019) (finding applicant’s evidence of continuous use of ALGAE WAFERS since at least Oct. 31, 1991 and advertisment of the goods sold under the mark since at least Oct. 1992 did not convince the Board that "ordinary purchasers of fish food have come to view that term primarily as an indicator of source"); In re Uncle Sam Chem. Co., Ser. No. 73392627, 1986 TTAB LEXIS 162, at *8 (1986) (holding §2(f) claim of acquired distinctiveness persuasive where applicant had submitted declaration of its president supporting sales figures and attesting to over eighteen years of substantially exclusive and continuous use).

To support a §2(f) claim, use of the mark must be use in commerce, as defined in 15 U.S.C. §1127. See TMEP §§901–901.04 regarding what constitutes use in commerce.