Six months after Snapchat launched its publisher portal Discover, the mobile messaging app has dropped two media companies in favor of ones that would appear to appeal more to Snapchat's young audience.

On Monday Snapchat replaced Yahoo's and Warner Music Group's Discover channels and added channels for BuzzFeed and iHeartRadio. A Snapchat spokeswoman did not immediately respond to a request for comment sent Monday morning asking about the reason for the changes.

Snapchat rolled out Discover in January 2015 as a way to give people a reason to spend even more time in the app that was originally used for sending expiring photo and video messages to friends. The publishing portal launched with 12 channels that included CNN, ESPN, Vice, People and Daily Mail as well as Snapchat's own channel. Each channel posts a daily roundup of anywhere between 5 and 20 stories that range from long, text-heavy articles to single-screen stories meant to be shared to vertical videos.

While it's unclear exactly why Yahoo and Warner Music Group were given the axe, neither of the two companies' channels appear to have been particularly lucrative for the two companies or Snapchat, which lets Discover partners sell ads against their channels and takes a 30% cut of the revenue (50% if Snapchat sells the ads).

"As we continue to find unique opportunities to reach people with our content, we're looking forward to continuing to work with partners, including Snapchat, that can bring our live video and other properties to new users," said a Yahoo spokeswoman in an emailed statement.

Ad Age has been logging the daily editions of each Discover channel since July 13. In that span, Yahoo has only run two ads; both aired on July 20 and promoted Ford. In the same span, Warner Music Group has not run any ads. For what it's worth Snapchat's own Discover channel hasn't run any ads over that same two-week period.

Re/code reported last Thursday that Snapchat would be dropping some publishers from Discover and adding new ones.