Recent spike in our membership numbers has been interesting… took us years to get over 1000 and then within a few months we get over 500… and a lot of those in just the last few weeks.
Is it spammers or something else?
I’d say 70% spammers and 30% fans. Nobody has bothered to delete spammers accounts. I bet at least 1/3 of total members have been banned! 
Usually we have about 160 active members (which I think means members who have signed up in the last 60 days)… for the last few weeks we’ve had twice that, and probably less spam than I remember. I think we’re getting more traffic to the site actually.