Quidco is brilliant.
I have earnt £670.81 since I started using it in January 2007. Obviously the recent Virgin payments are a big chunk, but there are other tricks you can use to build up your cash, the best being the Insurance cash backs. When you get your home insurance, its very important you split your buildings and contents insurance policies, rather then get a combined...that way you double your cashback. I have even used the same insurance company and had 2 policies with them, and gotten twice the cashback....and of course theres nothing wrong with doing that, its not fraud or anything, its just clever.