Google Alerts is a free service offered by Google that will alert you to new content that Google finds on the Web that contains the keywords that you specify. Google Alerts is most often recommended to monitor your brand and brand of your online competition. But I also use Google Alerts as a way to discover new affiliate programs in my niche.
Access Google Alerts and enter a keyword for the products or services in your niche followed by the Expression Affiliate Program. As an example, type the phrase SEO Affiliate program in the search box for alerts: