By Valve's own numbers, a game usually makes ten to twenty times more money during a sale than at full price, even with the price cut in half. A few titles pull seventy to eighty times more.
The developer of each game sets its own discount and chooses whether to join the sale. Steam just runs the store and takes its usual cut, about a quarter of each sale in 2025, even less for the big sellers. So a 20 dollar game at half off brings in 10 dollars: Valve keeps roughly 3, the developer keeps 7. Both sides earn a bit less per copy, and neither one is covering the other's loss.
A lower price still wins, for two reasons. A digital copy costs almost nothing to make, so there are no unsold copies piling up in a warehouse. And a sale reaches buyers who were never going to pay full price. For a five-year-old game, almost every one of those buyers is brand new, someone who would have skipped it at full price.
The sale also solves a discovery problem. Steam has 146,012 games, and 20,018 of them launched in 2025 alone. A game older than a year barely gets noticed on its own, so joining a sale is often the only way for it to be seen.
That 90 percent in the meme is the literal ceiling. Steam caps any discount at 90 percent and blocks anything under 10 percent, and the deepest cuts go to old games that already paid for themselves years ago. The 2024 summer sale sold around 876 million dollars of games in two weeks.
Valve runs the whole operation with about 350 people and an estimated 17 billion dollars a year, close to 48 million dollars of revenue per employee. Apple makes about 2.4 million per head. It is the most efficient business in tech, and it runs on selling copies that cost nothing to make, to people whose libraries are already more than half full of games they have never played.