Software king of the world, Microsoft, is looking to buy itself a chunk of a social networking site.
Foursquare is slightly different from your usual social not-working site in that it is location-based primarily for mobiles.
Users "check in" at venues using a mobile website, text messaging or a device-specific application by selecting from a list of nearby venues that the application will locate, and can share relevant tips.
It has been around for a while and was launched in 2009 by Dennis Crowley and Naveen Selvadurai. It works on iOS, Symbian, Series 40, MeeGo, Android, WebOS, Windows Phone, Bada and BlackBerry, and PlayStation Vita.
What has been a breakthrough for the outfit is that it has worked out a way for advertisers to target users when they arrive in a particular area.
The big idea is to give Microsoft a bigger boot in the door of social media and mobile which are areas where it has little impact.
Foursquare has been getting closer to Microsoft by making an application for its Windows 8 operating system.