Q: How do I find the right percentage of payout to give affiliates?
A: There isn’t really any Golden Rule here, rather it comes down to what’s happening in your particular vertical.
I’d suggest looking at your competitors to see what they are doing and how much they are paying, and use them as a guideline.
You don’t want to pay out less than competing affiliate programs, and just the same, it doesn’t make sense to far exceed their commission rate.
Ideally, you will dig into your margins to pay some degree more than the competition to set your affiliate program apart from the pack.
Of course, this is just one piece of the puzzle. Your site has to convert well, too, in order to keep the affiliates happy.