For every $2500 you put on it, they send you a $25 Amazon gift certificate.
With such a wide variety of stuff available on Amazon, we usually have no problem finding something on there that we were going to buy anyway, in essence getting it for free.
Basically, that’s giving you 1% back in a semi-liquid form, and they give you 3% on things you purchase at Amazon and 2% back for certain gas stations and restaurants. No annual fee.