Infospace announced in April that it planned to add Microsoft support to Dogpile before the end of the summer.
"MSN Search has only been live since December. That they have enough confidence in MSN Search is a great endorsement for MSN Search this early," said Nathan Weinberg, founder of BlogNewsChannel.com.
"Google was around for years before it became the leader. MSN is doing a great job at improving its search engine at a fast enough pace that they are included. It gets their name out there, and shows that people are confident in their results."
"MSN Search is a terrific addition to our metasearch capability," said Richard Pelly, vice president of search distribution, Infospace Search and Directory, in a statement released by Infospace.
"As the only provider to have relationships with all four of the most popular algorithms, we are able to offer a search solution uniquely designed to provide end users with the most relevant results and support our partners business agendas."
"It was important to include MSN Search in our metasearches because 70.8 percent of their search results are unique only to MSN," said Brian Bowman, vice president of marketing and product management for InfoSpace Search and Directory.
Dogpile is one of several branded metasearch sites from InfoSpace, which also owns WebCrawler, MetaCrawler, and WebFetch.
Displaying search results from Google, Yahoo, Ask Jeeves and MSN Search, alongside each other, Dogpile also shows "best of all search engines" results that are a mixture of all 12 of the search engines with which Infospace contracts.
Others include About.com, FindWhat and LookSmart.