Valve's first conference for developers working on Steam and Steam Machines begins today, and brings with it some interesting statistics about the service. 

According to Valve's press release, the number of active Steam accounts grew 15% over the holiday months to 75 million.  The publisher also put its 2013 sales revenue in a geographical context: North America and Western Europe account for 41% and 40% of sales (respectively), while South America and Eastern Europe have 2% each. Russia and Brazil grew the most from 2012 to 2013. 

The chart below has the full breakdown. Hopefully we get more cool info like this as the two-day Steam Dev Days conference continues.

Our Take
Most gamers are already familiar with Steam's success, but that kind of growth over the course of a few months is still impressive. Building that user base will be an important endeavor if the company hopes for its Steam Machines to gain traction.