Here is one part of the answer Megan Fox, her drawing power in a action flick is huge with the boys of all ages.
I find that hard to believe. No chick is hot enough to make guys shell out 10 bucks to see a movie when they can see hot chicks on the internet for free.
Transformers is a popular brand. The title draws people in. You could put any chick in that role and it would be the same result.