Barbara Feldman: Google AdSense: CPM or CPC?

Google AdSense: CPM or CPC?

Although the Google AdSense agreement prohibits publishers from disclosing CPM or CPC figures to others, it is important that you calculate these rates for yourself. And once you've done that, you can easily compare your Google AdSense earnings to those from alternative ad sources, such as Fastclick or Burst Media (both of which I still use.)

KEY:
R = total $ revenue
I = total number of ad impressions
K= total number of clicks

FORMULAS:
CPM = R/I * 1000
(or in English: revenue divided by impressions times 1000)

CPC = R/K
(or in English: revenue divided by number of clicks)

Everyone's results with Google AdSense will be different, but these CPM and CPC figures will give you the apples and oranges you need to evaluate the alternatives.