Here is some information about genre and gender
I did a bit of research and found out that in 2009 503 films were released in the UK from many different genres, yet only 31 were thrillers.
Out of this 503, 52% of these films were either action, animation or comedy. I think these genres are most popular mainly because they appeal to a wider target audience instead of just one main one. For example, 'Toy story 3' which was release on the 19th of July 2010, appealed to its usual young audience, yet in order for them to be able watch the the film they would have gone with an adult. I also know teenagers who went to see this film as it was a continuation of a classic Disney production.