Page Impressions

I have just set up 4 url channels on my adsense account,but can someone explain what page impressions mean ?

 

1.
google adsense page impressions typically might be MUCH lower than your real page impressions according to your own ACCURATE access_log stats

2.
adsense page impressions is the number of times a page has been viewed
that number typically is needed for all CPM advertisers
as in 1. that number may be MUCH smaller ( a fraction ) of real page views. I assume that G uses the balance for additional profit.

normally the pageimpressions G adsense shows is near the number of unique visitors I have on my site

 

Thanks For The Info.

 

For me is pageimpressions G adsense about twice more than unique visitors but still not enough as real pageviews...

 

I dont think it is true because my adsense impression is 3-4 times of my visitors most days!

 

Same for me,
my stat 150 uniques
Google impressions would be some like 160 impressions
Very close.