This guy claims that his wordpress site had a turnover of over 6 million yesterday (March 19 2013). This may or may not be true, who knows, but let's assume it is for the sake of argument. His average commission is likely to be around 50 bips, judging from his fee schedule. After all, since you can't get more than 1000 bucks out per day, few people will be gullible enough to do larger trades.