Ok, there was quite a bit of discussion below about where the money is. In verticals like e-commerce, it is indeed dominated by about 100-200 players. These gu

Ok, there was quite a bit of discussion below about where the money is. In verticals like e-commerce, it is indeed dominated by about 100-200 players. These guys range from RetailMeNot which is owned by Whale Shark Media to companies like FatWallet and Ebates. There is actually a big variety of major players in the space, but still most commissions are concentrated with them. If you get into CPA, there's many, many more players out there. I know a few personally that make ~$100k+/month and one that does $500k. However, the commissions aren't concentrated with them. There are thousands of players making $5k-$15k/month with campaign churn. They tend to be 1-person shops working on the latest hot offer. CPA is very crowded but is easy (sort of) to break into. There's a lot of money to be made, but you also deal with a huge amount of fraud and competition. I was able to make a very comfortable living as an affiliate in high-end lead generation and B2B, both places where it was extremely difficult to compete with me. There are many segments like this where time and being willing to pick up the phone are often all the competitive advantage you need. However, what happens is you can build a business or a site or do the campaign churn. People that build sites make some money for a while but are often crushed by more dedicated competitors. People doing the campaign churn (they don't own sites, just advertise stuff and make money off the difference) can keep going for a while, but have to constantly seek out new advantages. Last, the ones that build businesses make the big bucks. And they often become more than affiliates, seeking to sell the products themselves or vertically integrating in their chosen space. One I know was dealing with travel and eventually became the booking agency for his vertical. No one can compete because he has exclusive direct relationships - the same advantage I sought in my own verticals. There is a ton of money to be made, but it is a field fraught with risk, fraud, deception and hyper-competitive people with far fewer scruples than you. I chose to leave the field after making my pile and build the tools I always wanted when I was in it - a much better business overall.