The easiest way to explain Ebates is that they give a percentage of your online purchase back to you quarterly. The amount you receive at each store is different and in order to earn the cash back you just need to link through Ebates to the shopping site.
Purchases you make at Ebates stores are only credited if you start your shopping session at Ebates.com and click to a store via an Ebates link. I have had an Ebates account since 2001 so I am a long time user. I have received about $500 back from ebates over this time period. This is not a ton of money but not too shabby just for an extra few keyboard clicks on things I was planning to buy anyhow.
If you don’t have an ebates account already, now is a great time to get one. If you sign up through my siteyou will receive $5 in your account just for trying them out.