And therein lies a critical flaw in your reasoning. They are not the same movie. They do not necessarily have the same audience. On one hand, you couldn't pay me to watch Transformers, my loathing for both that stupid afternoon cartoon and Michael Bay being what they are. On the other hand, Spidey 3 was the worst of the Spidey films, yet I still liked it enough to buy it. You could find 100 other people here on this forum who would disagree strongly with both of my sentiments about both films. Comparing the sales figures of both leads nowhere and proves nothing.