Banner advertisement can be very useful, but only when employed correctly. Be sure to make your banner "fit" with the site you are advertising on, and keep the banner simple and specific in terms of content. As far as design goesbe creative! Always view your work with a critical eye, and wonder if you would click the banner if you were a visitor to the site you are advertising on. If you follow these guidelines, you could generate a lot of traffic to your site for a relatively small investment.