Foursquare Hits 4 Million Users

Updated: A long time ago, someone wrote a book with the title “The First 20 Million Is The Hardest.” Of course, the book’s title was all about the first 20 million dollars, a lot of money in the quaint old days of Silicon Valley. I suppose you can extend the analogy and say the same about getting the first million users for a service. Once you get those, the rest is gravvy. (And to think that there was a time when 100,000 was a good enough target to achieve.)

Testimony for that comes from Foursquare, which has now passed four million users, according to co-founder and CEO Dennis Crowley. In a conversation earlier today, Dennis said that it took a mere 50 days for them to grab a million additional users. The location-based service hit the 3 million mark in August 2010. It’s clear that Foursquare is starting to see a network effect — the more people sign-up, the faster it grows.

Foursquare hit the one million user mark in March 2010, a year after the service launched. The company has been making feature additions to the service that allow it to attract a more mainstream audience, and in an interview earlier this year, Dennis shared with me his grand ambitions of marrying the social web and location. Getting to 4 Million users is only part of that grand scheme.

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