Technically, Hulk merchandise may have sold more than Spidey 1's merch, but there are a few reasons for it.
1. No one thought Spidey 1 would be the blockbuster hit it became. Therefore, there wasn't the usual flood of tie-in merchandise we've come to expect for these type of movies.
2. Hulk merchandise didn't live up to retailer/vendor expectations which were based on the run-away success of the Spidey.
So technically, Hulk merchandise sold a lot. There was also a tremendous amount of Hulk merchandise sitting around on store shelves, since the movie didn't live up to anyone's expectations (at least financially). There was so much unmoving Hulk stuff clogging store shelves and pegs months after the movie's release, that Toy Biz had a hard time getting retailers to order a spin-off line of comic book based Hulk "classics" toyline. Toy Biz may have made a lot of money from stores ordering Hulk merchandise. However, stores don't make money if the product doesn't move off shelves. Therefore, TB/Marvel could say, "hey we made $50 million off Hulk toys!" while WM could say, "hey we lost $5 million off Hulk toys!"
Anyway, my point is this....word is good on vendors/retailers being interested in the new Hulk movie. This is quite a tidbit of news, since there was a perceived (and justified depending on which side of the fence you sit) "failure" of the first Hulk movie. Hasbro is already banking on the Hulk being popular by launching 2 comic book-based Hulk lines next year, as well as the obvious movie stuff.
Combined with the potential juggernaut of Iron Man (based on such outstanding buzz 8 months away from its release), Marvel should easily rule next summer. Sure, Dark Knight will do well. However, Batman Begins didn't light too many B.O. fires (and underperformed in many a eye). DK should due better due to the Joker. However, both IM and Hulk will be more family friendly with more colorful heroes and new ground to tread. I think they'll be the 2 summer movies to beat next year.