More data. Nielsen Online’s ad impressions per month, via Clickz.com (paid CPM display ads only*.)
First, the raw data.
Broken out by category, sorted by change from August 08 to today: largest decline on top (software), largest increase on bottom (telecommunications.)
Change in four largest categories, and total, since February 06 (Feb 06=100.)
And percentage of impressions by sector. This one’s a bit psychedelic.
* Per Nielsen: “Nielsen Online, AdRelevance service uses a proprietary methodology for estimating online advertising expenditures and only takes into account image-based technologies and advertising sold per CPM. Above data does not reflect house advertising activity, strategic partnerships between publishers and advertisers, or text units, paid search, sponsorships, email, units contained within applications (e.g., messengers and pre-rolls) or performance based advertising. “