I can't get into too many details, but in the past 5 years, I did some consulting for a small company that did nothing but affiliate sales.

I don't know what their total revenue was, but I know that they were paying for 3 full-time consultants billing on the high-end, 1 graphic designer, a full-time accountant, a business manager, 3 SEO people (full time as well) and the owner.

So, there is definitely some money to be made there, I just don't know the actual ratios of blood, sweat and tears vs. sheer luck.