For what it's worth, I've got two totally unsubstantiated, completely back of the napkin theories on why THG has had this OW.1. A synergy effect between Twilight/Potter: Not perfect crossover. But those audiences grew up with two event franchises and were ready to embrace a 3rd when they got older which combined with the new young base THG enjoys. So it's base was actually larger than Potter/Twilight before you add in the 4 Quad. Maybe this is too obvious.2. The books: Not a new theory, but a new twist. Everyone talks about the volume of books. Tons of movies have had more books in print in print prior to a movie release than THG. I think timing is the more important factor. HELP had a high number of active readers in addition to big sales when it was released. TWILIGHT the same. But I'll bet if you could quantify it, THG had the highest volume of active readership in the 6 months prior to its release than any film in memory, maybe in history.