As a frequent web user you probably know that the Web is growing fast, however, do you understand the market forces that drive it? Have you ever wondered why there's so much information on the web, and so many web sites? Have you noticed that the web has become the infrastructure of the new electronic marketplace?
What drives the market is Advertising!

Advertising is how a successful business tells customers about its products and services. Advertising is what can attract people to come in and browse around—and hopefully buy something. You see plenty of advertisements in the local newspaper every day, placed by businesses who want you to know more about them. Major television stations are no different. On the Web, businesses often place banner ads in high-traffic areas of the Web. These "click-through" ads are carefully designed to entice users to visit their site and learn more about what they have to offer. Maybe you'll be interested, maybe you won't. The objective is getting you to the site so you can find out.

A good banner can only be effective if it is placed correctly on the web.
Always, always place your banner on sites that cater for your target audience (i.e. - the people most likely to buy your product). There's no point putting a banner for a new golf club you sell on a site dedicated to software, visitors to the site simply are not going to be interested and you're just wasting your money. Hence, take out the time to do necessary research on where to place your banner ads. Wise thinking before will lead to maximum profits later.