Online Ad Spend by Industry - January 2008
Note: Nielsen Online’s AdRelevance service uses a proprietary methodology for estimating online advertising expenditures and takes into account only 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.
These are invaluable data points! Any chance 2009 or 2010 updates are available