Well, it takes a bit of time to learn what pics wlil elicit what reactions on getbig.
Based on what I've seen, I'd say it's something like this:
Pic of weird looking chicks / female bodybuilders - about 2 pages of comments, at a rough 1:3:12 ratio of schmoe approval:'manlier than' comparisons: plain dissing
Pic of normal chicks - seldom get posted and never elicit any comments
Pics of hot chicks - about 6 comments, at a rough 2:2:2 ratio of 'I'd hit it':'I've had better':*insert minor physical flaw* is why I won't hit it
Pic of man in thong - about 5 pages of comment, ranging from schmoe admiration to hater dissing to Bay telling everyone they are gay
Pics of men in thongs - anywhere between 30 - 3000 pages - these are the most popular and active threads, and the reason this site gets all the traffic it does