The affiliate program with my particular host works like this:
The first full month's payment (could range from $24.95-$1000 for each new account)
10% of the lifetime of the customer
Considering it's a zero cost venture for me, it's a good deal. it gives me free hosting with unlimited everything, so I can't complain.
If you're doing sites and not making money from setting up hosting, then you should start something like this. Find a good hosting company, local is good because if they're slow on payments yo can march right in and pick it up.