I don't see why not. If you have a solid plan of how you are going to sustain your affiliate program and cash to back it up, it could be a very good idea.
Judging from hundreds of "web hosting review" sites that pop-up like mushroom all over the web, companies that really get noticed are those that offer the largest cash renumeration.
However, you do not have to compete against them. Set the price you are ready to pay and that makes good business sense and use your existing client base to spread the word. Your current satisfied clients is your biggest marketing weapon you have, so utilize it!
