Microsoft adCenter has been live in the UK for a few weeks. Today the beta for Microsoft ContentAds has opened to selected Microsoft advertisers. I first saw the story on Jennifer Slegg's blog JenSense. TechCrunch writer Marshall Kirkpatrick followed up with a story as well.

This is big financial news because the truth is the search business is all about delivering contextual ads with high CTR (click through rates) along side relevant search results. The media focus has been on the search index, relevance, size, and speed which are the table stakes for this game. The real money is made by delivering ads.

Yahoo had been delivering ads for Microsoft sites, but last year Microsoft launched a service to deliver its own ads for its own sites. Microsoft adCenter extends the service to all advertisers for MSN Search and other Microsoft sites, and eventually to all web sites.  Microsoft adCenter will be a full service competitor to Google's adSense and Yahoo's Publishing Network.

JenSense points out "ContentAds will also be utilizing demographic targeting, geo-targeting and incremental bidding tools for all advertisements as well, so advertisers will have full flexibility on their ads appearing through ContentAds."

TechCrunch says "More big time competition for Google’s AdSense, Yahoo! Publisher Network and the other players in the field should mean higher revenue cuts for publishers and more innovation in the way ads are served."

This is probably boring to most people but this is where the battle for advertising dollars is won and lost. Targeting ads by demographics, geography, time of day, variable and incremental pricing, are very important to advertisers.

I believe adCenter will have very advanced click fraud detection that will filter out invalid clicks far better than Google or Yahoo. This will make a big difference to advertisers.