Sovrn uses lijit.com as its ad serving domain for historical reasons: Lijit was the original programmatic company that became Sovrn, and all of Sovrn's programmatic advertising services still operate on the http://Lijit.com domain today. Seeing lijit.com in your ad requests or ads.txt file is expected and correct.
A brief history of Lijit and Sovrn
Lijit was a programmatic advertising company that was acquired by Federated Media in 2011. In 2014, Federated Media's programmatic ad business — the former Lijit — spun off and rebranded as Sovrn. The lijit.com domain carried over from that lineage and remains the technical backbone of Sovrn's ad serving.
What the http://lijit.com domain does
Every Sovrn programmatic advertising service is operated on the lijit.com domain. It handles all network requests to the Sovrn Ad Exchange, and Sovrn's third-party advertising cookie references lijit.com. All of Sovrn's programmatic advertising partners call the lijit.com domain for functions such as cookie syncing. Sovrn is TAG Platinum certified — TAG's highest designation for the fight against fraud, malware, and piracy — and ads served through lijit.com do not contain malware.
Do not remove http://lijit.com from your ads.txt file
You should not remove lijit.com from your ads.txt file. If you do, many of Sovrn's advertising partners will no longer recognize that you're selling through the Sovrn Ad Exchange and will stop buying your inventory, which will significantly reduce your monetization. Sovrn currently has no plans to migrate off the lijit.com domain, as doing so would require coordination across all publishers and advertising partners.
Questions? Concerns? Our team would be more than happy to help. Reach out to our Support Team here.