Google AdSense v Microsoft PubCenter

Which search engine has a better keyword based advertising strategy? Google has established themselves firmly with AdSense, but Microsoft is attempting to tap into this rich market with its own twist on the ad market, called PubCenter. Check it out here: http://advertising.microsoft.com/publisher. They have a mode similar to Google’s, but pilot tests have publishers reporting more traffic from PubCenter than Adsense. This may be because PubCenter allows advertisers to add pictures in addition to text.