2017 was Steam’s most profitable year yet, claims Sergey Galyonkin and the creator of SteamSpy, a website that, since 2015, has provided estimates on the number of game sales on the titular digital game store.

The digital store made revenues of $4.3 billion in 2017, a large proportion of which, he claims, was facilitated by the popularity of Playerunknown’s Battlegrounds, the unrivaled hit of last year. There are now 291 million Steam accounts, 63 million of which were created last year.

Speaking at GDC 2018, Galyonkin revealed a slew of statistics that show the yawning gap between the winners and losers on the service.

“Half of all the money is made by a small subset of games,” he said. In fact, of the 21,406 games currently on Steam (7,696 of which were released in 2017) those that manage to break into the top 100 make the majority of the money.

PUBG has sold, Galyonkin said, close to 28 million copies, generating $600 million in revenue. This is followed by Counter-Strike: Global Offensive, with 12.5 million sales, and revenues of $120 million.

A game must make $22 million in gross revenue to break into Steam’s top 20, a figure which has remained the same. “Hits like these are what make money for Valve.”

This data has been harvested by Galyonkin’s SteamSpy, which works by monitoring around 800,000 user profiles each day, using a three-day sample to estimate the basic statistic’s via on Steam API. Galyonkin prefaced his talk by saying that Steam Spy does not work in real time -- it takes four days to “catch-up”, he said -- and is “not precise” and “very inaccurate” for small games.

The technology only tracks owners and players, not sales, is unable to distinguish between games sold on Steam, sold elsewhere, and given away for free, and currently does not track refunds.

Nevertheless, Galyonkin is confident in stating that Steam “is not slowing down”. 57 million players were active in the past two weeks, he said. 25 percent of all Steam account holders have played a game in the past two weeks, he said.

“It’s not all great through,” said Galyonkin. The median user owns only two games, while the mean average is 10.8 games, numbers which have fallen in recent years.

While the service is not as saturated at the App Store, Galyonkin said, "discoverability" is becoming a major issue on the platform; around 30 games launch each day, more than one per hour.

“We have too many games,” he said. “It’s not only impossible for a user to buy them all; it’s impossible for a user to even scroll through them.”

While China is the largest market, the most represented nationality on Steam is American. “13.9 percent of active players are American, said Galyonkin. "And the average American use buys six times more games on Steam than an average user from China.”

The number of Steam accounts has risen sharply in 2017, said Galyonkin. This is because Cybercafes in China are “installing Steam so their clients can play PUBG,” said Galyonkin. The average Chinese player spends more than twice as much time playing PUBG than the average American.

The fastest growing game tag on Steam in the past five years is “dinosaurs, ” followed by “conspiracy.” The number of games tagged “Team-based” and “PVE” have fallen the greatest in the same period.

As well as running Steam Spy, Galyonkin also works as director of publishing strategy at Epic Games. “Our publishing strategy at Epic Games,” he quipped, “is to not put our games on Steam.”