robho - 9:18 pm on Jan 11, 2005 (gmt 0)

To add a couple of things which are sometimes misunderstood:

Page Impressions DO include PSA's (Public Service Ads) and Alternate Ads. Clicks DO NOT include clicks on PSAs or Alternate Ads. So if you get a high proportion of PSAs/Alts the CTR will be inaccurate (no longer shows the percentage of paying ads that are clicked on).

Page impressions can be much lower than other stats you may have because impressions from javascript-enabled browsers are not included. So impressions from virtually all robots, link checkers, and from the small percentage of users who don't use javascript, are not included.

But really Macro I think you've hit the nail on the head which would answer most questions: never take the slightest notice of any stats until they are at least a day or two old! It's just a recipe for high blood pressure.