Buckle up, because we're about to combine the two most exciting parts of PC gaming news: exponential user growth and graphs! Last Sunday, Steam hit 6.6 million concurrent users. It's an impressive figure, but what's really surprising is how it stacks up against previous totals. Back in January 2012 the service was hitting a high point of 5 million, with them not reaching the 6 million mark until November. That means Steam is currently growing around 300% faster than it was at the start of last year.

So where are those players coming from? To the graph-o-matic !

Essentially we're seeing massive and steady growth for the (technically) unreleased Dota 2. Less than six months ago the game could beat the then top-dog TF2 in concurrent users, but couldn't surpass the daily peak. Now it's a different story. The latest Steam stats have Dota 2 way ahead with a peak concurrent total of 237,414 players. In second place, still enjoying a post-Christmas boost, is Football Manager 2013 with 78,488 players. Team Fortress 2, meanwhile, has been consistently fluctuating between 45,000 and 75,000 players.

It's a big number, but still one far behind League of Legends, which was pulling a reported 3 million concurrent users as of July last year.

Dota 2 still doesn't account for the majority of Steam's overall user growth, despite the flood of free beta keys it incessantly sends out. And, of course, concurrent users don't give the full picture. We still don't know how many of those are active, or even the collected number of players who log into any particular Steam game over a set period of time.

Even so, it's a great sign of the health of PC gaming. It will be interesting to see how those figures change over the next year, as the console manufacturers creak into life to reveal their upcoming new hardware.