Yahoo claims that banners burn out after two weeks. According to research, banners that appear when a page first loads are more likely to be clicked on. Negotiate ad placement on the top of page when buying space. The best possible scenario is having banners placed both on the top and on the bottom of a page. Link the Banner To a Specific Page, Not the Homepage.
Nobody wants to plow through a corporate home page to get to what they want to see.
Link them directly to the advertising offer or create a transition Web page that will lead them down the sales cycle. An unreadable banner will get a very low click through rate, as will a 'busy' banner - overflowing with lots of words or differing images. Many of the top performing banners have less than 6 words, and most of the words are one syllable. Terse and clean. 10 Banner size.