Page Impressions vs. True Page Views

[sailorjwd]

You-all may have already discuss this but here goes:

I've noticed that my Adsense page impressions are consistently 8% to 12% less then ~true page views as calculated from another source.

Does anyone else have similar data?

I've also noticed that sometimes when I goto pages on my site I see no Adsense ad at all, not even a PSA. If I refresh I see the ad. Anyone else experience this?

[blasto333]

Page impressions that don'y count are from people who do not have javascript enabled.

[sailorjwd]

Ooohhh.. its tough being a newbie in this business... I guess there are a few percent decrease also because once in a while ads simply do not appear - per my limited experience.