We already knew that Microsoft is determined to do anything to gain more market share for its Live Search engine. And it seems like “anything” is not just a figure of speech.

Today at advance08, Microsoft's annual advertising customer event, Microsoft Chairman Bill Gates announced the company’s latest trick to attract the users to use its search engine: Microsoft Live Search Cashback.

The idea is simple: the users who wish to buy something can use Cashback to find their desired object. In case they complete a transaction, Microsoft’s program will reward them with cash rebates ranging from 2 percent to 30 percent.

Those users who are willing to enroll in Microsoft’s Cash Back should sign up for a Live Search cashback account at the time of their first purchase. They will receive the rebates in their cashback account directly from Microsoft 60 days after completing purchases.

Microsoft Live Cash Back is based on the technology acquired by Microsoft in October 2007,  when the company bought the comparison shopping site Jellyfish.

Microsoft has already enrolled in its service an impressive number of companies. Names like Barnes & Noble.com, Circuit City, Cookware.com, Crutchfield, eBay, HP, Jockey, TigerDirect.com or Zappos.com are just some of those to be found on complete list of Live Search cashback partners.

Last year, Microsoft’s Live Search has gone through a major technical update, dubbed as “the biggest update since our debut in January 2005.” Redmond’s engineers have focused on improving the relevance and they apparently achieved that by quadrupling the size of Live Search’s index.

Microsoft said at the time that it had come up with a new way of extracting data from the Web which automatically adds information from specific domains to the data base, including ratings and reviews; businesses (locations, contact information, photos, hours of operation, ratings and reviews); celebrities (buzz, images and videos) and more.

Despite it’s the company’s efforts, currently, Microsoft’s Live Search engine trails behind Google and Yahoo, having a market share of 11.3 percent in the U.S.