Banners are the most common type of Web ad, and they come in a wide variety of sizes.
Through generated when a user clicks with their mouse on an advertiser's message in order to move to the advertiser's Web site. Impressions the number of times an ad banner is requested by site visitors' browsers and presumably seen by the user. Guaranteed impressions are the minimum times an ad banner has the opportunity to be seen by visitors. Hits is not the preferred term for site traffic measurement because the number of hits per page varies widely. There are an average of six hits per page.