Affiliate programs are now one of most popular ways for webmasters with lot of traffic to their sites to earn good money.
There are many factors which influence amount of money earned by an affiliate. The most important is quality of affiliate program. So if you want to make lots of money, you must know how to choose an affiliate program.
First of all you should look for a web site that has been on net for some time. That's how you know that you can trust them and you will receive money you make. There are many untrustworthy programs that fooled a lot of webmasters with promises but they never sent money.
Next step is to check quality of products site is promoting. Don't advertise a product if you wouldn't use it for your self. You shouldn't be blinded by high commissions an affiliate program is offering. If you join a program with bad products you will damage your image and you won't be able to advertise other products ever because people won't value your opinion.
Try to find an affiliate program with a good commission rate because you don't want to waste your time if you can make much more money elsewhere. A good commission would be a 20% to 25% of product price.