Part of Megavideo's appeal is the availability of entire TV show episodes. I've been using Megavideo to catch up on David Duchovny in season 2 of Showtime's Californication. Showtime hasn't given me a way to buy a DVD or a download of the second season, which ended months ago.
The ripped episodes uploaded to Megavideo aren't high-resolution, but the entire episode plays immediately and without sputtering. Why bother with BitTorrent?
Megavideo has plenty of non-copyright-infringing clips, like this scary Turkish train accident. But this complete 22-minute episode of the Japanese cartoon One Piece has been watched nearly a million times.
One mathematical caveat: ComScore's Top 10 chart makes clear that while #1 YouTube accounts for 43 percent of online video watching, #10 Megavideo only accounts for 0.7 percent. Through YouTube, Google's dominance over video traffic is catching up to its dominance in search.