I was wondering if there is a way to give my affiliates more than 15% of my sales commission.

I think 15% is too low and it doesn't give an incentive for the affiliates to promote my products.

Is there a way that I can go into my account settings and change it from 15% to 50%?

Thank you.

The maximum is 20%. Affiliates can be pushed up a tier if they exceed a certain level of sales.

Only the CP Affiliate Team can increase the commission rate, it's not something an SK can do.

15-20% I think, as an affiliate myself, is a pretty good incentive.

Erm... thoughtful of you but...

a) not in any way that I know of that would work
b) while you could feasibly give away 50% of your markup, you couldn't give away 50% of CP's base price, so it wouldn't end up being 50% of the product anyway and would be confusing as all get out for you or an affiliate to figure out.
c) If you ever look at affiliate programs, 15% is pretty good. Much of what I see come to my inbox as an affiliate is 8 - 10%.
d) You aren't the one the affiliate has an agreement with. It is CafePress.