A reader wonders:
if my Adwords ad shows up on page 4 of a search, and the searcher never gets to page 4, does that count as an impression? It was potentially available to be seen, but the searcher quit before getting to page 4.
Or does an impression occur ONLY when the searcher actually views the page where my ad is located?
It’s only an impression if the searcher brings up the page with your ad on it. So in your example, if you’re on page 4 that doesn’t count as an impression.
That’s why, in your 80/20 AdWords management practice (described in AdWords For Dummies), you must check the average position of keywords after sorting by impressions descending. The total number of impressions is the limit of your market – unless you’re bidding too low to take advantage of the whole pool.