Some of it is no doubt users that initially don't understand the ramp/5nd/payout system here at first and miss the daily payouts. Others may have been users that try out different pools. There really is no telling. For all we know some users were using multiple BTC addresses for workers and then created a user account instead. Who knows, maybe Kano. What I know is no matter what, we are growing in hashrate, and we are going to MINE ON!