AdSense click-through rate

How is it calculated?

[mayor]

I'm trying to figure out what Google's AdSense click-through rate really means.

Does each adword count as an impression, or is it the group of adwords that are displayed on a page that count as one impression?

[bether2]

Comparing my pageviews (in my own stats) to my Adsense impressions, I would say that each group of adwords is one impression.

Maybe someone else can confirm this (or say otherwise).

Beth

[rcjordan]

>each group of adwords is one impression

That seems right, comparing log stats to adword reports.