Website Ars Technica has spent some time trawling the publically available user data of more than 170 million Steam accounts in order to find out just what people are playing and, perhaps more interestingly, what they're not playing.
The study was compiled in order to give a more accurate reflection on the performance of top titles on the gaming service, as Steam is notoriously secretive about its sales figures, but the information gathered makes for far more interesting reading than simple sales numbers.
However, once you start taking a look at the percentage of people who've actually played each of the top titles, the picture begins to change a little.
DotA 2 has been played by almost everyone who has installed it, but Half-Life 2: Lost Cost has only had 2.1 million people play it in comparison to its 10.7 million installs. Other high-install, low-play titles include Day of Defeat (5.6 million installs, 2.8 million players), Deathmatch Classic (5.6 million installs, 0.4 millon players), Ricochet (6.4 million installs, 0.3 million players) and Half-Life 2: Episode One (3.1 million installs, 1.7 million players).
Astonishingly, 36.9% of games purchased on Steam have never been played. Not once. And a further 41.6% of games sold have only been played for between 1 minute and 10 hours, suggesting that many Steam users tend to purchase first and think later.
You can find out some more interesting stats by checking out the full Ars Technica article here.