This table can help you to decide what type of ad banner is best suited for your company. You'll notice that there are other types of ad banners listed here that I have not discussed. This is because my computer cannot load these types of banners. This brings up another important point. The technology you use in your advertisement must match the technology of your potential customers. If they can't see the ad, chances are they won't buy the product.
I got this table from Adinnov.com