Microsoft is unleashing its Content Ads program on August 26, opening up what has until now been a small beta test of a system that targets ads to the content of Web pages. Now all U.S.-based advertisers will be able to place ads via Microsoft's Content Ads, which hopes to do for Microsoft's MSN websites what AdSense has done for websites partnering with Google: Blanket them in context-sensitive, keyword-based advertising. While many speculate the Content Ads program will put Google and Microsoft in close ad-selling competition, and foster advertiser-friendly price and technology wars, Microsoft still has a lot of catching up to do in market share. AdSense is already widely deployed across the blogosphere, and has become the default business model for unimaginative startups everywhere.