Every time someone uses that link, someone (is that you, Tom?) gets a small payment for driving internet traffic there.
I did a search and found a large number of places that claimed your linked site was a scam. There were a few who dispute dthose claims, but for all I know, those were by the owners of the site or people who were getting their 1 cent per hit for referred traffic.
Tom: I'll only give one warning to you and to anyone else who puts such adverts on this Forum:
Don't.This topic is now closed for business.
[update]
I found five separate threads where this link had been posted. I have removed them all, and taken a very dim vew of this sort of behaviour.
[update 2]
Apparently this is a pyramid selling scam. If enough people click on the link and pay their three pounds, someone (Tom, I assume) gets his free iPod.
Each of the people paying their three pounds then have to get a huge number of other people to click on their link and pay three pounds, and so it goes. But they can't all get enough people, as there aren't enough people in the world.
This is pyramid selling. Those who get in first get the goods, but no-one else does. By the time you are in the fifth row of people to apply. You're simply fodder.
This type of scam is illegal in the UK, Europe and the USA, at least. It was banned ove 50 years ago.