Just watch the clip from BBC's NewsNight program. It explains exactly how this type of advertising campaign can actually work!
This clip refers to "freeipods.com", which was the original rewards website for US residents only, but the principal is exactly the same as the UK based websites referred to on this site.
And if you're still not convinced? Then check out our Articles page for some newspaper article extracts.
Ready to get yourself some free goodies? If so, head to the Free Stuff page.