46,463,575 registered users. Two things immediately come to mind here. 1. how many of these huge social networking sites are there out there, and how many of t

46,463,575 registered users. Two things immediately come to mind here. 1. how many of these huge social networking sites are there out there, and how many of them (like this one) have I never heard of? 2. yet again it's free, so what's their revenue model. If this posting was just spam to HN, or put here to generate discussion, I just can't tell.