The real money earner. Every site that I've mentioned so far, has affiliation deals. It means that if YOU sign up to the site (which of course, I really hope you do!) they pay me a little backhander for getting you to sign up. It can be as much as a fiver per person, so you can easily see, that if you manage to get ten folks signed up to one of them thats fifty quid in your back pocket.....if you happen to be a member of 5-10 sites and get the same ten folk to sign up to all of them......
So, that, in a nutshell, is it! I really hope you consider signing up to one or two of the sites i've mentioned, and get yourself a bit of tax free pocket money. Have fun with it, don't take it TOO seriously, and remember - you won't make �30,000 a day, - but you might just make enough to pay for next years summer holiday.