Kitty is spot on with her review.
FF has one of the largest memberships of any (paid) dating site (20+ million members currently), though this is a bit misleading:
1) There are reports that this number is inflated, due to fake and inactive profiles.
2) The total membership is spread out over quite a few countries. As with any dating site you're considering, I recommend using alexa.com to find out what percentage of the total membership is in your country (if you're unsure how to do this, I recently recorded a video in which I cover this
http://su.pr/1GmQQq; it's towards the middle of the video).
3) Compared to other sites, there's a higher than average percentage of male members (which is great for Kitty, I assume, but less so for you). However, this percentage varies from region to region. So I recommend testing the site out (with a free membership) to see how it plays out in your region FIRST before paying for an upgraded membership.
Hope this helps.
Best,
Dan