CPM: the acronym CPM stands for "cost per thousand impressions". This refers to an advertising model used in online marketing. In this pricing model, the advertiser pays a flat fee for every 1,000 impressions their ad has on the publisher's website. In this case, an "impression" refers to an instance where their ad is displayed. In other words, the advertiser is paying for the cost or expense of showing the site's users their advertisement, regardless of whether the viewer clicks through or converts to a paying customer.
One of the most difficult parts of analyzing CPM is counting and defining impressions, especially when a website displays multiple ads on the same page. As a result, page counting typically excludes page refreshing and other user options as instances of impressions. Advertisers and publishers using this model should therefore discuss how impressions are to be counted before utilizing this method.
CPM is also used as a method of assessing the cost and efficacy of an internet advertising campaign. This is the closest method of analyzing an advertisement offered in other forms of media, including television and print, which sell their advertising opportunities based on their estimated number of viewers or readers. As a result, it can also be used to compare an online advertising campaign with one promoted through other mediums based on cost.