Just in time for the holiday season, Microsoft and Google are engaged in a bitter dispute over who is the fairest search engine for online shopping - the latest battle in the war between the two tech giants.
Microsoft's argues on their newly created page, "Scroogled", that its rival has reversed course on its pledge at the time of the Google stock offering to avoid paid ad inclusion for search results.
"Google shopping it nothing more than a list of targeted ads that unsuspecting customers assume as search results" Microsoft claims.
Google announced earlier this year it would revamp its product search to become a shopping service with paid listings. This eliminated merchants which opted not to pay, including some notable ones such as Amazon.
Microsoft has been busy campaigning on and offline with ads "demonstrating why consumers should be concerned and helping them take action" on the Google shift, a Microsoft statement said.
"We're also calling on Google to stop this 'pay-to-rank' system for their shopping results and give shoppers what they expect - an honest search."
Google maintains that merchants cannot improve their ranks simply by paying more, and that sellers who have a financial stake in the results will keep their information up to date.
Less than transparent
But some analysts say both companies are less than transparent about how their shopping engines work, and that Microsoft is not without blame.
Danny Sullivan, analyst with the website Search Engine Land, said of the Microsoft effort: "Great campaign, if it were true. It's not. Bing itself does the same thing it accuses Google of."
Sullivan told AFP news agency that "at least Google has the fine print that you can read; Microsoft doesn't have it at all."
He noted that Google merely adopted the same policies of most shopping sites, which use paid listings even if they appear to be an impartial search.
Microsoft, according to Sullivan, excludes new merchants from Bing search results if they do not pay for inclusion with its partner, Shopping.com, even though this is not fully transparent to consumers.
"Payment is a factor for ranking," in Bing, says Sullivan, who maintains that Microsoft's campaign is misleading.
Microsoft says its own shopping results through Bing are not influenced by payment.
"While merchants can pay fees for inclusion on our third party shopping sites... we do not rank merchants higher based on who pays us, nor do we let merchants pay to have their product offers placed higher in Bing Shopping's search results," said Stefan Weitz, senior director at Bing, in an emailed statement.
The overall message from the latest row, according to Sullivan: "You need to shop around. Use multiple search engines. All of them that suggest that they are gathering stuff from across the Web but may not be doing that."