10% is... umm... alot. The processors already eat up a ton of the profits, and when you figure in paying affiliates, buying content and plugins, paying for bandwidth, etc. that 10% is HUGE.
Another thing... you pay affiliates, right? But you only pay once a month AND you pay 28 days AFTER the end of the pay period? That means that if someone starts promoting a program on the 1st of the month, it'd be about two full months before he got his first check. I doubt many affiliates would go for that. I only use a couple of monthly sponsors, and I use them only rarely. My main sponsor pays weekly and my secondary sponsor pays twice a month. Recently there was a poll about this subject and a pretty big chunk said they preferred weekly payouts or at least every two weeks. The only people that really liked monthly seemed to be people with so much money that cashing a check more than once a month was just too time consuming for them!
Seriously. Lower that percentage and pay more often and you might get a few people signed up.