Its pretty simple... when you click on the shopping section, you'll see a list of store websites and the percentage amount of cash back you'll receive if you shop through that link. Click on the link and shop as usual. That's it. Here are few stores that offer cash back through CashCrate.
Apple iTunes
Blinds.com
Champs Sports
Enterprise Rent-A-Car
Flower.com
Foot Locker
LEGO Store
Magazines.com
Microsoft Store
Mrs Fields
Office Depot
and more...
If you shop there anyway, you might as well get the cash back, than not get it .....right? Makes sense to me.