Snapchats publisher portal Discover has recently turned six months old, and has been making considerable waves in the mobile marketing world for the high rates it has demanded for advertising.

Now, the company has dropped two of the media companies involved in generating content for the service in favour of brands more likely to appeal to the apps crucial teen audience.

Both Yahoo and Warner Music Groups Discover channels were dropped on Monday morning, and replaced by channels for web publisher BuzzFeed and streaming service iHeartRadio.

According to Advertising Age, in the two weeks preceding their exit, Warner Music Groups Discover channel showed no adverts, while Yahoos showed only two, both for Ford and both on 20 July. However, Snapchats own Discover channel has also not shown any ads during the same two-week period, so a lack of advertiser interest isnt necessarily to blame.

That said, much of Snapchats ability to demand such high ad costs is its access to teen and pre-teen users, and channels that dont take advantage of that audience are likely to quickly fall to the wayside.