Urchin v/s Adsense, differences grow

how much variation is normal

[whizkiddo]

I use Urchin for my webstats. So far Adsense and Urchin while never in complete agreement with each other did not show much of a difference in page views. The difference was around 5%

However since the past 10-15 days, the difference has grown to 15-20% and thats a lot.

1) As far as I know Adsense counts PSA or alternate ad servings in its page views, am i correct?

2) Does Urchin count spider crawls as pageviews? I mean what else could be causing such a large difference.

Or could it be that Norton blocking and incompatible browsers are causing this difference. What kind of differences do ou folks see?

[adfree]

10-15% normal with me and Urchin 5.

[jimh009]

Urchin also counts spiders as a pageview, so that is always going to inflate your pageview count a bit - especially on those days when Googlebot or Yahoobot hit your pages hard.