Snapchat is pushing to sell its own advertising across all its Discover channels, by asking some publishing partners to relinquish their exclusive advertising rights, according to sources cited by Digiday.

Some publishers within the Discover content channel had exclusive rights to sell advertising to brands, an agreement that initially helped bring advertising sales to the platform. But with early publisher advertising agreements soon expiring, Snapchat now wants to add that inventory to its general pool of available advertising space.

Snapchat doesn’t have an online advertising marketplace like rivals Facebook or Twitter, so it has relied on selling advertisement space through its sales representatives, or through partners, such as its Discover publishers. Some of the app’s Discover publishers include Buzzfeed, Vice and Comedy Central. Snapchat gets a cut of revenue publishers earn on its platform.

Though partnering with publishers boosted advertising revenue initially, now Snapchat is faced with advertising inventory that is controlled by various different parties and priced inconsistently. Consolidating control of advertising inventory would help Snapchat sell more advertising to clients who want to place ads across multiple channels, based on targeted demographics such as age, gender and location.

“Snapchat is pushing hard on publishers to give up exclusivity on inventory and allow them to sell inventory on an audience basis,” Digiday’s source said.

Snapchat also announced last week that Discover advertising performance will now be measured by rating agency Nielsen, which will make it easier for brands and agencies to compare advertisement performance on Snapchat to other social media platforms.

Technology reporter Garrett Reim can be reached at [email protected]. Follow him on Twitter @garrettreim for the latest in L.A. tech news.