Banners are the most common type of Web ad, and they come in a wide variety of sizes .
Buffer pages are typically hosted by the Web site on which the ad is running, rather than appearing on the advertiser's site. Buttons typically link to an advertiser's site or a buffer page. They are generally used for sponsorships or downloadable products. Sometimes referred to as the response rate. Conversion can be as subtle as attracting users to your site, or as dramatic as convincing them to buy your product.