User blog comment:Brandon Rhea/Intro to Wiki Modernization/@comment-5558012-20170306204035/@comment-20644-20170306204245

Good question! No, they are not ads. When this project is completed, featured videos like those will have pre-roll ads in front of them. Think of it like YouTube. When you open a video, a video ad plays. Then your video starts to play. Same thing would apply here.

Right now we don't have pre-roll ads on the test videos, since we're focusing on what kind of content resonates with users and what the best placement is for videos. But we'll probably be doing tests that have pre-roll on them too.