Last August, there were reports Microsoft was poised to make a strategic investment in Foursquare Labs . On February 4, Foursquare's CEO told the Wall Street Journal that Microsoft had invested $15 million in the company.

According to the Journal interview with Foursquare CEO Dennis Crowley, Microsoft also signed a "multi-year contract to license Foursquare data in services such as its mobile operating system and Bing search engine."

The Journal story claimed that as a result of the deal, Microsoft is now Foursquare's single biggest source of revenue.

Foursquare is a social-media company which enables users to check-in from various locations and post those check-ins on FaceBook, Twitter, and other apps and sites. In 2012, Microsoft announced that Bing was integrating Foursquare data via the Bing Sidebar.

Microsoft has been working to beef up its social-networking portfolio in the last couple of years. The company bought enterprise social-networking vendor Yammer in July 2012 and has been integrating Yammer across a number of its products and services since then.

I've asked Microsoft for comment on the Foursquare investment. No word back so far.

As Fast Company pointed out, although word of the Foursquare investment was made public on February 4, the day Microsoft announced Satya Nadella is its new CEO , this investment really isn't Nadella's first big move as CEO. Supposedly Microsoft and Foursquare had been working to finalize the deal over the past few months. That said, Nadella has been a champion of Bing and big-data at Microsoft.