The numbers don't look good.

You should analyze the waiting periods for the account approval and their effect on the retention. When I've joined in January this year, I've waited about three days. Two guys I persuaded to join waited for over two weeks in February.

One lost interest completely, didn't even bother to vote or post anything. The other wrote the intro post, got "Welcome Message" by the bots, saw what's trending and lost his interest.