Affiliate marketing is not about being lazy and making cold hard cash all day while you sit out in the sun.
The truth about the affiliate business is that it takes hard work. Ask any successful marketer and they will say the same thing.
It is really all about helping other people make informed decisions before actually buying a product. This is exactly like a commissioned salesperson at some retail store.
It works though. As long as you are willing to work hard. Set up affiliate sites that are targeted towards on keyword each. Make sure you rank high for each one in the search engines, mainly google.