AvatarJames Cameron's'Avatar' is not only beating the fourth-weekend box-office record of Cameron's earlier 'Titanic,' but it's beating it by nearly $25 million. Sunday estimates projected a fourth-weekend gross of $48.5 million for the current runaway hit. The record set by 'Titanic' in January of 1998 was $28.7 million. If the estimate stands, 'Avatar's' 24-day domestic total is now at $429 million.

But before we faint from the size of these numbers, it's time for a reality check, time to bring Cameron's Pandoran adventure back to Earth. The true measure of a movie's popularity is the number of tickets purchased -- aka "admissions" or "number of butts in seats" -- and at that, 'Avatar' is far, far from the top of the list.

First of all, 'Avatar's' reported ticket sales are skewed upward by the higher prices being charged for 3-D and 3-D IMAX showings. More important is a little thing called inflation.