The second trailer for the upcoming Dark Knight Rises (which I'm really looking forward to, as both a huge Batman fan and a big fan of Christopher Nolan's work) has broken records on Apple's iTunes movie download site, boasting a full 12.5 million downloads in just 24 hours, topping the previous record by 2 million. That's a pretty solid debut for the "exclusive" trailer (exclusive, in this case, meaning it's popped up on other video sites after its debut).
That previous record was held by none other than Marvel's The Avengers preview, which came out earlier this year. Obviously downloads like these don't make any money for Apple -- they instead cost a lot more money, both in bandwidth and in things like technical support and oversight. But of course releasing free trailers like this promotes both the movie and the iTunes download service -- that's 12.5 million people who, when they want to go and download or rent a full movie, know where iTunes is and how it works. From Apple's point of view, that kind of promotion is well worth it.