Foursquare hosted 2B check-ins across 20M users

On its third annual 4sqDay, Foursquare celebrates its success at getting people to check-in

As I opened my Foursquare application to check in this morning, I noticed that today is the third annual 4sqDay and all those checking in today will receive a badge signifying their celebration of the social check-in networks' birthday. Also coinciding with this anniversary is the company's announcement that it has buzzed right through the 20 million user mark and has hosted more than 2 billion check-ins to date.

You may remember when Foursquare broke through the 15 million users mark last in December, and just last month the company said the next milestone of 20 million was within reach. 

Location-based services and check-ins took a while to find their way. At first a lot of people were interested in deals and gamification badges but were worried about privacy since they wanted more control over who saw where they were and when.  Now check-ins have been folded into all social networking services and often come with their own perks, such as coupons at retail locations and connecting with people you have common interests with. 

Foursquare was a pioneer in this field and, while it has taken longer to grow its pool of users, the company has been making some great partnerships with small businesses and big brands such as American Express. And with one of its biggest competitors, Gowalla, was snatched up by Facebook, Foursquare has had time to test out new services and build its platform to include restaurant deals, exploration and discover features and partner with communities to build awareness about events in the area.

The New York City-based company has raised more than $71 million in funding so far with the latest round of $50 million last June bringing the company valuation to $600 million.

So with Foursquare proudly boasting that it added five million registered users in the last 16 months, the company really has a reason to celebrate this 4sq Day (which, for all the math fans out there, is 4/4^2).

While checking-in services still have a long way to go, a December 2011 study from Forrester Research found that just 5% of U.S. adults use any location-based check-in services, the growing demand for mobile payment services and loyalty programs that base their deals on location devices and check-ins may help push the trend further in to the mainstream.

In fact, just last week another location-based discovery company built a new app based on the demand from small businesses looking to get an edge in the mobile revolution. Loku, a location-based restaurant discovery tool, acts as a constant updating stream of local information that changes according to your location.  

While Yelp relies on user input, Loku mines the Web using a local analytics engine to pull updates and reviews on events from social media and the Internet.  

Since the site's beta launch last September, user acquisition has seen 50-80% growth month-over-month.  Currently, some 60,000 users check in regularly using Loku.

And every new mobile payment app on the market is pushing the idea of discovering and checking into retail spots in order to get deals and give small businesses good buzz.