The independent stat tracker Steam Spy has revealed some sales info for Steam’s 2015 game sales. The paid games market, not including DLC or free-to-play games, is estimated at $3.5 billion on Steam alone. The two biggest months for Steam this year were December, thanks to the winter steam sale, and April, thanks to Grand Theft Auto V‘s PC release.

A few interesting tidbits came out of Steam Spy’s analysis. It broke out sales and copies sold separately, giving us a good idea of how popular games are separately from how much money they make. Grand Theft Auto V and Fallout 4 top both lists, but it shifts pretty wildly from there. Metal Gear Solid V: The Phantom Pain, Counter-Strike: Global Offensive, and The Witcher 3: Wild Hunt round out the top 5 most profitable games, while the other three best sellers after the top 2 were dinosaur sim ARK: Survival Evolved, Rocket League, and H1Z1. 

Once Grand Theft Auto V hit the scene, it didn’t (and still hasn’t!) left the top 5 best sellers list. The Witcher 3: Wild Hunt spent most of the year in the top 10, with the incredibly release-heavy month of October being the only notable omission.

The lists, shown above, are an interesting mix of independent and mainstream games, confirming the power of word of mouth with those smaller scale games versus marketing juggernauts like Grand Theft Auto V.

Check out the source link below for a full, in-depth breakdown.