When people think viral they often think it comes down to all us humans switching onto something and sharing it like crazy. In fact, very traditional marketing techniques matter. Like celebrity endorsement.

Take Samsung’s dominance of videos over the last week. As Ad Week reports Samsung’s YouTube video for its music-streaming Milk service includes cameos from Iggy Azalea, Little Dragon, Childish Gambino, John Legend, Lady Antebellum, Cold War Kids and Chromeo. The video has 22.8 million views, 458 tweets and more than 9,500 Facebook Likes.

Sure content matters. But endorsers and talent really matters in the world of viral.