150 referrals, wow. Do you experience some kind of saturation by now, in that it becomes increasingly harder to find a potential new user who hasn't yet subscribed?
actually I don't put any work into getting referrals at all, so I don't know. I wrote a blog post about it and put the link on twitter a few times, and the referrals just keep pouring in - I'd love to know where they all come from to be honest! I've hit the limit as to my free space allowance now.
