Reddit is set to offer advertisers across North America promoted posts in its mobile app starting Monday, extending its native advertising play to one of its most active platforms.

The new unit (which bears a “promoted” tag) places advertiser content in-stream with the up-voting, down-voting and commenting tools typically given to organic user content (distinguishing it from Reddit’s standard mobile ads). The new ads can be targeted by interest, community, geography and device.

Similar native ads had previously been available on the site’s desktop and mobile web platforms. The app ads will launch on iOS devices on March 19, with Android app ads set to roll out in the coming weeks.

Reddit’s mobile users represent a massive chunk of its overall user base. The site reports that 41% of time spent on Reddit happens through its mobile apps. Of Reddit’s mobile audience, 80% don’t use the site’s desktop version. According to a company spokesperson, app users spend 30% more time on the site per day than desktop users.

Reddit remains one of the few remaining online tribes where brands are hesitant to tread. Its active and highly engaged, but sometimes toxic communities have demonstrated hostility to brands’ attempts to join their communities (although there are a handful of brands that have had tremendous success becoming relevant parts of the community).

Not every conversation on the platform is ideal for advertising either (googling “worst Reddit threads” will provide a glimpse of its darker corners). But a Reddit spokesperson says the company provides a “hand-curated whitelist” of communities it deems safe for advertisers, and reviews individual posts within those communities to avoid negative ascendancy.

Despite these dark corners, Reddit remains a plum audience in terms of activity and size. It reports 330 million active monthly users who contribute an average of 10.7 million posts monthly. It tracks 46.7 million searches per day.