I could be wrong Stu, but the way I understand it is you can win cash each month by possessing them. The more you have, the more likely you are to win, with the top prize being £1million.

But the beauty of it is that you can cash your bonds in at any time, and you don't lose a penny of the money you've put in. So in essence it's like saving up, but with the added bonus of winning a large sum of money. I may be a little off, but that's as I understand it.

I'm not sure how they get the money that makes up the prizes though. My guess is that it's paid out of interest generated by the account that everyone buying bonds pays into. COuld be wrong about that bit though.