Owned and operated by Microsoft, MSN is a true portal site offering much more than just search services. However due to the strength of the Microsoft brand, it is one of the largest search engines in the world.

Paid Listings and Authorities

They draw their results from a wide variety of sources. From the top of the results page, we see "featured results", which are drawn from the sites of advertisers, sponsors and noted authorities.

Then come "sponsored sites" which are paid listings from the Overture Web Site.

Directory

Next are "Web directory sites" drawn from LookSmart.com

Database

The "Top 10 Most Popular " list is powered by DirectHit/Teoma. They also have the Inktomi results as filler where the LookSmart results are thin

With the recent consolidation in the search marketplace, MSN have begun the process of reducing their dependency on 3rd party data to fill their results pages. A new crawler, MSNBot/1.0, has been observed collecting data from the web, and MSN have begun a massive recruitment campaign for Information Retrieval professionals, which should ultimately lead to the creation of a new MicroSoft owned and run free search service.