Big difference between number of page impressions in Google adsense st

What is the problem!

[Etarwin]

Hi,
Anyone knows why there is a big difference between my real statistics for the page impression for my site and the statistics that appears in the google adsense control panel?!
For example I receive about 1500-2000 page impressions per day but google adsense show that I receive about 100 – 200 page impressions per day! About 90% less than the real one!
By the way the impressions that some robots make it is very little about just 50 page impressions per day.

[razinkane]

Maybe Google doesn't have ad inventory for your site?

[Etarwin]

Thank you for your reply razinkane but actually I did not understand your question, what is ad inventory!

[hunderdown]

They don't have ads with keywords that match the keywords for your pages. Are you seeing ads appearing on all the pages, all the time? Or are you seeing the Public Service Announcement ads?

[sudhirmangla]

Yes I also notice the same from past few days

[Etarwin]

No they have many ads that related with m keywords.

Anyway I contacted them and they told me that there are many clients disable javascript.
But their reply did not convince me.