As long as SM3 makes enough to spawn a Spider-Man 4, who the hell cares. You people act like you've bought stock in these films, or you've chiped in on the budget. Superman didn't even make back any of its production budget/marketing cost at the box office and it's getting a sequel, mainly because it has idiotic partners behind the film...but that's another story.
SM3 doesn't need to beat Shrek or Pirates to be successful. This is just something fanboys want to happen, when it need not be so. SM1/SM2 got beat by LOTR and Harry Potter worldwide, does that make Spidey films any less successful, I should think not.