it works like this way:

1) you must have an account on fatwallet.

2) you must click throught fatwallet's store URL to get to DELL (or other stores).

3) after you click through, there will be a small popup window, telling you the confirmation number.

4) after about several days (maybe weeks), your fatwallet account will show up your cash back. So remember the confirmation number, in case they did not show up, you can contact fatwallet to ask.

5) after your rebate accmulate to certain amount (it was 50$ before, not sure how much now), you can request a check or paypal transfer to get the cash back.