Microsoft’s Cortana, the Windows Phone version of Siri, is powered by Foursquare

Google and Lenovo aren't the only companies throwing millions of pounds around in the wake of their quarterly earnings reports. Microsoft recently plunked down $15 million (£9.1 million) for a piece of Foursquare to help with the overhaul of TellMe.

Related: Windows Phone 8.1 screenshot leaks show revolutionary notifications menu

According to a Bloomberg source, it's all about the data for Microsoft. Foursquare's 30-million-strong user base has helped them amass a treasure trove of information that could provide a major boost to Cortana – essentially Microsoft's Siri – once she's ready to roll out.

Cortana is expected to make her debut with the arrival of the next major update to Windows Phone. Microsoft hasn't confirmed yet when that will happen, but based on information from previous reports, Windows Phone 8.1 could be arriving any time now. Build 2014 kicks off on 2 April and that could be the perfect time to launch. Why not release Windows Phone 8.1 when thousands of enthusiastic devs and partners have gathered to see what you've been working on behind closed doors?

Foursquare's private stash of location and recommendation data gives Microsoft a leg up in local search. They still have a lot of ground to make up on Google, but this is a step in the right direction. It won't just benefit Windows Phone users, either. There's a chance that Cortana will show up in Windows 8.1 update one, too. Laptop and tablet users — particularly those who've snapped up cheap seven and eight-inch Windows slates — wouldn't mind the on-the-go assistance.

Related: Cortana voice control tipped for Windows Phone 8.1

Now they just need to secure a deal with Intel so that Cortana can out-Siri Siri without connecting to the cloud.