Social proof

Uncertain people copy other people. A large view count, a verified tick, a pinned comment with thousands of likes, a recognisable logo in the thumbnail: each reads as evidence that watching is a sensible use of somebody's time. Packaging borrows the effect openly. It cuts both ways, since a low count on an old upload signals the opposite just as loudly, and the whole thing depends on the viewer seeing themselves in the crowd being cited. Proof from people unlike your audience counts for very little.