Technological progress has merely provided us with more efficient means for going backwards.--ALDOUS HUXLEY
IN THE WORLD OF ADVERTISING, NOTHING IS REALLY FREE. When you listen to a radio or watch a television show, advertisers pay the costs and earn the right to broadcast their messages any time they want. Most people tolerate radio and television advertising since they've grown accustomed to its constant interruptions.
However, in the world of the Internet, people have a much lower tolerance level for advertisements. While advertisements pay for many free web hosting services and free or low-cost Internet services, there's a fine line between product promotion and invasion of privacy. When you hear or see a commercial on radio or television, you can freely ignore it. Unfortunately, advertisements on the Internet aren't always like that.
Ideally, an Internet advertisement would pop up once and give you the option of making it go away. Instead, Internet advertisements not only pop-up (and keep popping up over and over again), but they may also track which web pages you visit, to determine your preferences, which would be like having a radio or TV that could peek into your living room to see which brand of potato chips you might be eating at the moment. To intrude upon your privacy, Internet advertisers use a variety of tools including web bugs, adware, and a never-ending cascade of pop-up windows.