With banner ads you have flexibility. You are not limited to one kind of ad to advertise your product or service. With banner ads you have many different sizes and shapes to choose from. The Internet Advertising Bureau lists 8 standard size banners based on pixels. You will want your Web site to load clean and fast, so remember that banner ads affect the loading of your Web page. The bigger and more elaborate the banner ad, the slower your Web page will load. Remember, you have less than a minute to catch your customer's interest.