Glossary of Mobile Advertising Terms
1st Impression is the first ad to be displayed to a user in a predefined session. That session can be a single visit, a single day, or any other behavior/time format. Most often, it is used to describe the first time a user sees an ad in a day. Usually, marketers and advertisers use the first impression to track the delivery of intrusive or disruptive advertising formats, such as pop-ups, takeover ads or pre-home interstitials.
For example, a first impression takeover is displayed on the first page and can be also displayed on all website pages. Ad takeover ads are ads that give high visibility to the advertisers and they are usually found on homepages.
Another “strategy” for takeover ads is that you combine two ad units, one at the upper part of the page and the other closer to the bottom of the page. In some situations, like when you have an ad exchange with an RTB process, first impressions are used by either retargeting experts or data specialists.
First impressions are also usually linked to another term – First Touch. That is an attribution model when the first impression a single user saw gets credit. Not as common as Last Seen, but can be used to push media traffickers into broadening their searches.