Foursquare started as an app geared to a tiny segment of the world’s population: techies and nerds on the lower east side of Manhattan. Over time, more and more users joined, and it’s not really a niche tool anymore.

In other words, Foursquare has managed to answer the riddle that plagues anyone bringing a introducing a brand new product to any market: how do we get a critical mass of people to use our tool?

For commercial developers, being able to answer this question has direct bearing on a new app’s likelihood of success. For devotees of open source, it means something more. Getting bigger crowds to adopt tools built with open code not only makes for a successful app, it spreads the values of open source. This kind of success impacts an infinite number of new technologies.

That’s why its so cool that Foursquare has started using Development Seed’s MapBox – based on Open Street Map. Not only will more people will hear about the great work of Development Seed but, also, more tools will get better and easier for more people to use.  In announcing the collaboration, MapBox explains:

OpenStreetMap is open for anyone to contribute, which has proven critical, even in situations of crisis response. This means we will be able to continually improve MapBox Streets by contributing back to OSM any improvements we generate, while also pulling in changes from others. We’re confident this will get us to the most complete and useful maps on the web.

Is Foursquare, in switching from Google Maps to Open Street Map, trying to advocate for the open source movement? Doubtful – they probably switched simply because Open Street Map is better. Nevertheless, I don’t think it’s trivial that we’re seeing the closed and open source communities meet at maps: whether you’re trying to visualize crime patterns or find the best bar within a mile, mapping technology is essential. By virtue of their wide scale applicability, are maps an important entry way for niche toolbuilders and/or open source technologists to reach wider audiences?