Search Engines and Favoritism from Google Operating System has put together a quick study comparing the top results from Google, Yahoo and Microsoft’s search engines. The results showed that for 10 generic searches, the search engines (excluding Microsoft) tend to rank their own properties higher than their competitors.
For example, “Google ranked its own sites as #1 in 7 cases out of 10 and Yahoo in 6 cases out of 10,” said Ionut Alex Chitu. Ionut queried terms like mail, calendar, groups, toolbar, maps, desktop search, image search, video search, news search and search and plotted the results to show which engine ranked which engines where in their search results.
Google’s Matt Cutts denied that Google might give their own search results and preferential treatment.
If you’re talking about the algorithmic results, I can affirm that Google does not give any kind of boost to Google’s web pages.
Part of the differences may be how the companies choose to name and brand their products. For example, MSFT went with Hotmail rather than just mail, and they’re #1 for “hotmail.” Yahoo chose the name “local” for one of their services, and local.yahoo.com ranks #1 in Google for “local.” Google went with “Gmail” while Yahoo went with “Yahoo Mail,” so the #1 result for the search “mail” on Google is mail.yahoo.com.
I can’t speak to other search engines’ results, but I can say that Google doesn’t give any kind of boost to Google’s web pages in our algorithmic rankings.
All the search engines ranked Yahoo as the number one result for mail. But overall, it seemed like Google ranked their own properties higher than Yahoo or Microsoft, and Yahoo ranked their properties higher than Google or Microsoft.
You can create your own test cases at www.yahoogooglemsn.com.