What is a real impression?
Half or more of the site must be on-screen for one whole second before we count a website impression. A real impression is that has loaded entirely before the visitors has left the page.
An “impression” is counted as an ad being loaded fully on a site, whereas sometimes an “impressed” can be recorded when the server has partially displayed an ad.
It’s important to know if your ad is loading partially or completely. If you have an impression of 10,000 views for your report but only 100 clicks, then you may want to focus on increasing the click-through rate since that number doesn’t seem good enough.
However, if you were informed your ad only loaded 10% of the time, the click-through rate is extremely high and your campaign’s performance improves.
Speaking with your ad provider can help you determine whether or not an impression is loaded fully, but each impression may load at a different speed. You need to ensures that every impression always loads 100% before being counted.