It does not work. No web site is making a profit solely from showing ads to customers. Almost none are making a profit selling products to consumers. Even Amazon is in serious trouble today. As a sales and advertising medium to consumers, the web is a bust.
Lets see why that is.
The problem with making money by displaying ads on the web is that there are too many web sites. If you own the Cleveland Plain Dealer newspaper, you can make money selling ads to people in Cleveland, since you are one of the few games in town. It would cost millions of dollars to start new paper in a large city. You have competitors not just in your own city. They are all over the globe.