Banner Ads are online advertisements usually placed across the banner (the top 1/5) of a web page. They are a graphic image, usually a JPEG or GiF file. Websites sell advertising space by the pixel. A Banner Ad is usually 468 x 60 pixels. A banner ad is usually centered across the top, which enables the largest number of Internet users to be able to view the banner ad on any sized screen (including iPods and cell phones).