Impressions are the most basic form of online advertising. They are used to promote products and services by displaying them in a user’s browser window or on their computer desktop.
Impression rates are based on the number of times a page is viewed, not on how many people actually see that page. Impression rates are generally much lower than click-through rates (CTRs), because people can’t be expected to remember every single ad they see on the Web or in an email.
