Rather than take Google head on in the search wars which given Google’s dominance is probably an impossible feat, Microsoft is honing in on Google’s weaknesses instead. This strategy is apparent in its latest acquisition announced Sunday in which Microsoft purchased Greenfield Online, owner of Europe’s largest shopping price comparison website ciao.com, for a cool $486 million. Ciao.com provides online product price comparisons and user submitted reviews. Users are encouraged to write reviews by paying them a small amount for each positive comment received. That’s cool. Microsoft intends to expand this program by offering a cash back program for all users who purchase products through the site, not just US users who have been demoing this new feature for the past few months. Even cooler. Active in seven European countries, it receives 19.6 million unique visitors per month in Europe. Though hardly the purchase to finally propel Microsoft over Google, it may help Microsoft increase its market share, especially in Europe where it garners a pitiful 2%.