Personally, I have never tried posting on there. However, way back in the day, I tried emailing a couple of girls based on their posts, but never heard anything back.
I actually have a friend that is married to a girl that he met on there; she emailed him based on post. I never saw his post, but I assume the same applies as other dating websites -- read Chase's latest article on this (good pic, 2 paragraphs only, be interesting, give good reason why trying craigslist, etc.). But to be honest, he could do better. She's a little fat, but she has an amazing personality and is really friendly. I think they do love each other and will stay married, but if weight is an issue, don't bother. As far as looks, he could do way better.
Bottom line: I think it's a waste of time, and you'll have better luck at the other sites.