The people who make loads off programs like Google Adsense are the people who don't really need the money anyway - like huge companies that make millions of pounds of profit from their products and services.
If you want to make good money with your
website hosting (for example enough not to work) I
would not advise anyone to rely on this type of advertising. What do they pay $0.01 a click? - maybe less, so you need
200 unique clicks to make
£1. There are more profitable ways to spend your time!