you register, then on their site it lists all the discounts and cashback rates at the moment. You then click on the site, ebay,vodafone,sky pretty much all popular sites and more then carry on as normal, it then tracks your purchase and you get cashback at the advertised rate. They then put it in your bank. No hassle whatsoever, just got to remember to use the link to the site your buying off rather than going from google. So if you see something on a site you want write it down then go to quidco site, click on that sites link and purchase like that.