It's difficult to measure, but we kind of eyeball it by looking at the decrease in fake profiles with each thing we add. CloudFlare was hands down the most eff

It's difficult to measure, but we kind of eyeball it by looking at the decrease in fake profiles with each thing we add. CloudFlare was hands down the most effective thing we've done so far (by blocking users by country and/or by Project Honeypot info). It virtually eliminated all of the automated bot accounts and most of the human spammers. A couple of days ago I changed the signup process to use the Facebook Registration tool (under the assumption that Facebook is way better at weeding out fake profiles than we are), and that seems to be working pretty well so far. It's too soon to tell how it will affect our signup rates, but we'd rather err on the side of quality profiles. I'm also looking at running profiles through Mollom and some image-checking service I can't remember the name of if we still have fake profiles slipping through the cracks after all that, but we'll continue to go through the profiles every day and try to find the bad guys. We also gave a nice lady a lifetime premium account for reporting a ton of suspicious profiles when we were first starting out. :)