Make it clear the banner is something to be clicked.
Sales are more compelling than catch phrases.
Yahoo claims that banners burn out after two weeks. On the Infoseek site, banners seem to wear out after 200,000 to 400,000 impressions. If you opt for a rotating banner that features multiple messages, be sure to put your logo on each cell. Bigger Is better - Wider and large ad banners, typically 468 pixels pixels wide, are clicked on significantly more than smaller ones. Link them directly to the advertising offer or to a transition page.