Inception is #1 at the box office for the 3rd week in a row leading into August. That's a huge accomplishment. Summer movies usually get a week, maybe 2 at the top before a competitor comes along to take the top spot.
The percentage drop from one week to the next is much lower than other summer films. Usually you get a 60% drop off in business from opening number 1 to the following week. Inception is only dropping at a 35% rate, amazing. This is largely in part due to people going multiple times to see the film, as well as great word-of-mouth.
Lastly, the movie is an original! No comic-book, no sequel, prequel or reboot. This is a big deal. Rarely do we see original material last this long at number one. Similar to Avatar's longevity at the theater, Inception keeps rolling.
July 30th was director Christopher Nolan's 40th birthday, and what a way to celebrate. #1 Movie in America as well as single handidly showing Hollywood that audiences are yearning for original mater; just give it to us!
