Leonard0 - 5:41 pm on Dec 11, 2010 (gmt 0)
Match up your impressions to visitor count, you may be surprised to see that ad blocking is not that huge of an issue.
Wouldn't it be be better to compare page impressions rather than vistors?
Comparing my Adsense page impressions to my Analytics page impressions for November, I see a difference of 22%.
A more accurate way of detecting ad blockers would be to use one of the several ad block detection scripts available. It might be useful to set one up to track how many are using ad blockers and whether the trend is increasing.