Google yet remains the dominant search engine and all this deriding campaign by Microsoft point at one thing; its efforts to divert traffic on its own search engine Bing, which stands a distant second. The rivalry may get thicker in coming days.

Google defends its revision as an approach to encourage merchants to provide more comprehensive and accurate information about what they are selling. "I think you just get a well-organized set of product information, ways to buy it, and really have a great experience there," CEO Larry Page said during a conference call with analysts last month, reports IBN Live.

In a statement, Google said it's pleased with the responses for its listings of 100,000 sellers. And added Google doesn't require websites to pay to be listed in its main database, the index that provides results for requests entered into its all-purpose search box.

"Our search results are the best we know how to produce," Brin and Page wrote in the letter. "They are unbiased and objective and we do not accept payment for them."

The unexplained part is why Amazon, which offers some of the best deals on web, is not listed in Google’s shopping section of the search page.