CPA programs as they relate to internet income are short for cost per action programs. You make money when a person completes a specific action. Let's analyze this income stream a little closer. You can join CPA affiliate programs for free. The best way to do this is to join an affiliate network that offers multiple cost per action programs for you to promote. Your job really is to get traffic to your landing pages and play the Internet marketing numbers game. You will find a certain percentage of visitors to your landing page will complete the required action.