After doing a lot of research, I hired an affiliate manager. As a business owner, having an experienced affiliate manager work for you will free up your time and produce far better-results than you could.
The affiliate manager I hired works heavily with Commission Junction (so can get quick responses, push things through, and even provide discounts), and has a solid network of 10's of thousands of affiliates (thus able to promote my program rapidly).
Before this, I had my own affiliate program for the site, and was getting maybe a few signups per day. But by utilizing big hubs like Share-A-Sale, CJ, etc, I found the quality of the affiliates rose dramatically.