Microsoft adCenter (formerly MSN adCenter), is the division of the Microsoft Network (MSN) responsible for MSN's advertising services. Microsoft adCenter provides pay per click advertisements. This is a service aimed at people who want to advertise a product. Microsoft also has a (still in beta) service for webmasters who want to monetize on their site: Microsoft pubCenter.

Microsoft was the last of the "Big Three" search engines (Microsoft, Google and Yahoo!) to develop its own system for delivering pay per click (PPC) ads. Until the beginning of 2006, all of the ads displayed on the Bing (formerly MSN Search) search engine were supplied by Overture (and later Yahoo!). MSN collected a portion of the ad revenue in return for displaying Yahoo!'s ads on its search engine.

As search marketing grew, Microsoft began developing its own system, Microsoft adCenter, for selling PPC advertisements directly to advertisers. As the system was phased in, MSN search showed Yahoo! and Microsoft adCenter advertising in its search results. Microsoft effort to create AdCenter was led by Tarek Najm, then general manager in MSN division of Microsoft. In June 2006, the contract between Yahoo! and Microsoft had expired and Microsoft was displaying only ads from adCenter until 2010. In January 2010 Microsoft announced a take over of Yahoo! and the combination of Bing, formerly MSN Search, to form the Microsoft Search Alliance. A complete transition of all Yahoo! sponsored ad clients to Microsoft adCenter occurred in October 2010.

Coordinates: 47°38′22.55″N 122°7′42.42″W / 47.6395972°N 122.12845°W / 47.6395972; -122.12845

Microsoft Corporation (NASDAQ: MSFT) is an American multinational corporation headquartered in Redmond, Washington, United States that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions. Established on April 4, 1975 to develop and sell BASIC interpreters for the Altair 8800, Microsoft rose to dominate the home computer operating system market with MS-DOS in the mid-1980s, followed by the Microsoft Windows line of operating systems. Microsoft is one of the largest software corporations in the world.

Microsoft would also come to dominate the office suite market with Microsoft Office. The company has diversified into the video game industry with the Xbox and Xbox 360 consoles and the consumer electronics and digital services market MSN, the Zune and the Windows Phone OS. The ensuing rise of stock in the company's 1986 initial public offering (IPO) made an estimated three billionaires and 12,000 millionaires from Microsoft employees (Forbes 400 list revealed that in March 2011 both Jon Shipley and Nathan Myhrvold lost their billionaire status). In May 2011, Microsoft Corporation acquired Skype Communications for $8.5 billion.