Impressions vs. Pageviews, oy vey.

[smotheredinhugs]

I have yet to find a really articulate answer for the difference between these two, and which is the proper metric on which to base CPM.

My company gets about 325k pageviews per month site-wide. We sell ROS banners only. So, all of my CPM pricing has been based around this pageview count, which rises about 15-20% per month on average.

Two months ago we got an advertiser that delivered ads to our site through an iFrame (historically we have hosted the ads). This advertiser bought with us based on the pageview counts. To our surprise, the impressions they counted were less than 1/2 of our uniques (of which there are about 65k). Left us with an insurmountable gap to close. Yes, we had a cachebuster in place in that iFrame, and the delivery company they used is very reputable so I don't question the reporting validity.

I'm still baffled by which is the accurate measurement and pricing basis. Any help?

We use Urchin 5 if anyone has any particular places to look for the proper numbers.

thanks for any advice, cheers.

[jomaxx]

The only really accurate thing to do is put a tracking image (or page) in an iframe, possibly written by a Javascript cachebuster, the same way as the ad itself is being delivered. Then your stats should match the customer's stats reasonably closely.

What was the nature of the cachebuster in the iframe?