So, this has been bothering me for a couple of months. I figure it may well be a figment of the data, or I am abusing the data. But I don’t know, so I’ll put it up… comments welcome.
This is a graph of Implied Average Online Display Ad CPM, 2006 through Q2 2009 (left axis, thick blue line.) Implied Average CPM is ad spend divided by impressions.
The right axis and thin black line are impressions in millions, as per Thursday’s post. This seems to show that as display ad impressions fell in 2008, ad spend did not fall as fast. For this to happen, CPM must have increased. This is both not what has happened, anecdotally, and is hard to believe in this era of expanded access to non-premium inventory. But I hate to think I believe the data when it confirms my preconceptions and then disbelieve it when it doesn’t.
Are average display CPMs really nearing $7?
Anyone know what’s going on here?
Sources: Ad spend–TNS. Impressions–Nielsen Online. Both purport to be display only.