Today I ran a report on my adwords account and included CPM. I noticed that in November 2007 there was a DRAMATIC increase in my CPM. My CPM almost doubled in November 2007 and since then has stayed quite steady, but at this increased rate (almost double what it was pre Nov-2007).
Any ideas why this happened? What, that I could have done, would affect CPM so dramatically?
Any ideas would be great, thanks!
I have now run some more reports and noticed that after Nov 2007 my CPM went up with 84% and my impressions went down with 24%. I have been running my campaign for years and all trend were always quite stable - there was never such a major change as this. Also, I made absolutely no significant changes to keywords and cpc etc etc, so I cannot imagine that some like that could be the cause.
Any ideas please!? I am desperate to at least get some answers so that I can then concentrate on a fix/solution.
Tkanks!
