Yes...if his browser is set up so that he views the ad (javascript enabled) You can also count ad impressions in which case it counts each ad as an impression so in that case, impressions will be higher than page views.
Also, I figured out that impressions -> unique visitors... as well, does that correspond to your sites too?
If you only have one page maybe And probably not even then. One visitor may load several pages, thus giving several 'impressions' but only one unique visitor.
Yeh.. I've noticed that after I refresh it doesn't count as an impression.. so its probably at a per page basis!
I f someone comes on to a page with the ads showing but clicks the back button instantly, it is likely that it won't track as an impression created.
I'm guessing a per page per visit basis maybe. One visitor can make multiple visits through the day, and during each of those visits load multiple pages. So, do people count Visitors per day, Visits per day, Impressions per day? It also has to do with the type of refresh, too, probably. If you do a soft-refresh, probably not, if you do a hard-refresh, it does (at least when I've been editing pages and reloading content)
Impressions are counted uniquely. So if 1 person refreshes the page 500 times, it will count 1 impression. You can this theory by using a counter and see that the overall count on your webpage is way more than of Google. Peace,
I think it depends on the type of refresh...soft refresh may not count, but in my tests, hard refreshes definitely do.