I have been a longtime fan of Foursquare. The company is a pioneer in the location-based mobile space.

While many argue the ultimate value of the “check in,” I hold that this is a short-sighted view of Foursquare. Yes, the company built its brand on the back of checking in, but this was a means to an end. It was a way to engender optimal user behavior while building out its location database.

As Foursquare has moved away from being defined by the check in, the company has lost some luster in the eyes of consumers. Some in the tech world even predicted Foursquare’s ultimate demise over the course of the last year. Questions about the company’s annual revenue didn’t help it win supporters, but that is starting to change. Recent reports point to 2013 revenue of $10 – $15 million, which represents a 400% increase over the previous year.

Even through questions about the company’s long-term viability, I have held Foursquare to be one of the shining examples of our evolving mobile society. Foursquare’s API, which allows third-party apps to tap into its location database, is used by over 50,000 developers. Popular apps like Uber, Instagram, Vine and Path all rely on Foursquare data. This is Foursquare’s most valuable asset. Its the reason why Yahoo and Apple are banging down Foursquare’s door. With over 50 million points of interest, Foursquare can make the argument that it is one of the web’s most important location layers.

Thanks to its third-party app partners, even as check-ins wane, Foursquare continues to draw valuable insights from people’s location-based behavior. Every time a Vine video or Instagram photo is tagged to a specific location Foursquare gathers those signals. From that data, powerful inferences can be drawn about users’ broader behavior and intentions. This is immensely valuable to the likes of Google, Facebook, Yahoo, Apple and Microsoft as location becomes a more important part of search.

Rumors surfaced  in the last month about Microsoft making a strategic investment in Foursquare. This came on the heels of news that Yahoo wanted to partner with Foursquare to gain specialized access to its location data. Ever since Apple’s initial Maps debacle, Foursquare has been mentioned as an ideal company to help drastically improve Apple’s product.

With an acquisition price that would be in excess of $1 Billion, there are really only a handful of suitors that would make sense. The list includes Microsoft, Yahoo, Apple, Facebook, Google, and even American Express. I believe that any of these companies would greatly benefit from acquiring Foursquare.