33Across

Independent SSP with a differentiated focus on cookieless identity and attention-based ad formats for publishers

33Across is a New York-based AdTech company that operates a supply-side platform (SSP) focused on helping publishers maximize revenue through programmatic advertising. Founded in 2008, the company has built a reputation for innovation in attention-based advertising formats and cookieless identity solutions. Their platform connects publishers with premium demand sources while offering tools designed to optimize yield and audience monetization across display, video, and native formats. 33Across is particularly well known for its Lexicon identity solution, which enables publishers and advertisers to transact in a privacy-safe, cookieless environment. This positions the company as a key player in the ongoing industry transition away from third-party cookies. Their attention metrics and high-impact ad formats — including scroll-triggered and in-view units — differentiate them from traditional SSPs by emphasizing engagement quality over raw impression volume. In the broader AdTech ecosystem, 33Across serves as a critical infrastructure partner for mid-to-large publishers seeking to future-proof their monetization strategies. The company has maintained independence while competing against larger SSPs like Magnite, PubMatic, and Index Exchange, carving out a niche through identity innovation and publisher-centric tools. Their Lexicon ID has gained adoption across a significant portion of the open web, making them a notable contributor to post-cookie identity standards.