The #1 factor affiliates use when deciding on which products to promote are payout and conversion rate, possibly epc as well. If you can show that your product is going to convert for them, then guys will be lining up to promote it.
Your funnel needs to be proven to convert, people spend 1 or 2 days promoting you and if they don’t see any conversion they’ll drop you and never come back.
You need to know the lifetime value of your customers, so you can offer the highest payout possible. Get your back end setup, email list, remarketing/retargeting, upsells, and whatever other ways you can monetize each visitor. There are a lot of metrics that you need to know about your business, if you payout too high to your affiliates you could go bankrupt. Too low and noone will bother to promote you. Anyways the payout isn’t arbitrary, you need to have done research and know your business to set the price properly.
Of course all this depends on your product as well, different products have different methods.