Over last weekend, Geocaching.com, the website that made geocaching a popular outdoor sport, published its one-millionth active geocache listing.

Geocaching.com started almost 10 years ago when there were 75 known caches hidden in the world. According to Groundspeak, Inc., the private company created by geocaching.com founders, the web site published its 500,000th active hidden cache on New Year's Eve, 2007. It has taken just over two years to double the number of active geocaches in the world to reach the one millionth geocache.

Nowadays it is estimated there are more than 3 million high-tech treasure hunters in more than 150 countries.

As a private company Groundspeak does not publish any financial information but we can suspect they run a highly profitable business. In 2009 Geocaching.com had 1.2 billion page views and 82.6 million site visits. Groundspeak also launched its own iPhone application ($9.99) in October 2008 and has been in the top 10 grossing applications in the navigation category since then.

The company, based in Seattle, was created in 2002 - when the website started charging premium memberships – and currently has 40 employees.