To answer the actual question, You may notice above your question that there is an advert. People pay to advertise and revenue is gained from that. This can work in 2 ways, firstly on a simple display fee so I pay the website say �30 a month to show my sign. Or the second way is I will pay your web site 10p for every person who clicks on the link and visits my site. The more popular the web site the more money you can command. So for example to advertise on Google its many thousands of pounds a month (just had a quick look and they are talking 10,000 to 30,000 a month). One thing the internet has done as opposed to TV and Billboard advertising is that it has given the advertiser direct feedback on the number of people actively using the advert, so with a TV advert you can't really tell if spending �10,000 on a campaign is any better then �100,000 but with the net you can see the number of people comming in via an advert link and therefore see if your getting value for money.