Okay, I'll buy all of that but if the first Star Wars film sold zero action figures, I would wager we'd all still be talking about it. It was a compelling story with characters you couldn't forget. Chewbacca, C3PO, R2.... list goes on. Avatar? Not so much. edit: There's more to a pulp culture footprint than action figures. I own zero Big Lebowski action figures, zero Anchorman action figures, but damn if I haven't heard those films referenced a million times..
Star Wars was a different era. GI Joe didn't have a show, movie, or any other tie-in because that shit was illegal. We can all reference Rocky Horror, too, and it was also a commercial failure. You don't get to be an indie cult hit when you clear 2.7 billion at the box office. Fox pulled the trailer. They were actually stumped, the marketing department, God bless 'em, because they'd never come across a film that had so many genres in it. Was it a comedy? Was it an adventure film? Was it a kids film? Was it a fairy tale? Was it an adult movie? And of course, it was all of these things, you see. And they didn't know how to pitch it. The film came and did some modest business — respectable, modest, but not the kind of money that they hoped.
It wasn't until about almost a decade later when VHS came out that the film found its legs again — from a film that had been mostly dead, it was suddenly alive again. And then it became this huge hit.