If you want to get at large number of affiliates or partners, send application form right away.
Word of mouth is the best form of advertising there is and when you are hoping to make money as an affiliate, good reviews can be the difference between success and failure. This applies just as much to the companies that you are going to work with as well as the opinion people have of you and your website. The best way to get a review is to ask, but realistically you will have to know and trust the person you are asking. Once that review on out there it is hard to remove.