An impression occurs each time an advertisement is seen by a potential customer. For example, in online marketing, an impression happens when an advertisement such as a banner ad loads on a user’s screen, whether for the first time, when returning to a page, or when the ad cycles through dynamically.
Our article on the outline for a marketing plan can help you plan your advertising and marketing efforts, and check out our article on what metrics to track (and what not to track) on the LivePlan blog (as well as our entry on website metrics).