Very theoretical responses - I suppose Yeti had those thoughts before he posted. I think he is looking for something like "Yesss, our signup rate went up 50%" or "Nope, not really a difference".
It should give an improvement in registration rate as probably half our prospective/users are on facebook also (the other half are in other countries where facebook isn't so popular) but what I'm trying to get a handle on is how much it will drive new visitors based on friends of users seeing mini-feed updates back at facebook.
