Cost per thousand (CPM) is the most common method for pricing web ads in [digital marketing The method relies on impressions, which is a metric that counts the number of digital views or engagements for a particular advertisement. Impressions are also known as “ad views.” Advertisers pay website owners a set fee for every thousand impressions of an ad. While an impression measures how many times an ad was displayed on a site, it does not measure whether an ad was clicked on.
The [click-through rate CTR measures whether an ad was clicked on, representing the percentage of people who saw the ad and clicked on it. Advertisers frequently measure the success of a CPM campaign by its CTR, For example, an advertisement that receives two clicks for every 100 impressions has a 2% CTR. You cannot measure an advertisement’s success by CTR alone because an ad that a reader views but does not click may still have an impact.