Garry's Mod has sold over 3.5 million copies since its release

Garry's Mod has sold over 3.5 million copies, doubling in sales each year since its release in 2004. According to figures obtained by RPS, this past July was the game’s best in sales.

According to creator Garry Newman's assessment, it all has to do with "Steam’s ever increasing popularity."

"User generated content plays a massive role," he said. "Some of the gamemodes in GMod are like games of their own – so when a new gamemode gets released more people buy.
Team Fortress 2, Portal content. People play the games and want to play with their contents… we made sure to allow that stuff as much as we could."

Team Fortress 2 going free to play, Source Filmmaker bring released, the rise in useage in YouTube and Twitch, all have played a part in the Half-Life mod's popularity.

"If 15 million people see someone having fun in your game it’s going to make them want to play," Newman continued. "You’d think Minecraft would kill GMod’s popularity… but it’s kind of the opposite. People play Minecraft to death – they love it.. so they go out looking for other games that are a bit like it.

"Minecraft has attracted a lot of people that aren’t really PC gamers too. They play the game on the 360 or the iPad and everyone tells them that the PC version is better."

Newman also isn't stressed over his next game Rust, saying that he doesn't feel any pressure to repeat Garry's Mod's popularity.

"We decided a long time about to not give that much of a f**k about sales," he said. "We’re never going to recreate GMod’s popularity – it would be stupid to try. If we can make a game we’re proud of, it pays for itself and allows us to make another game – we’re very happy."

Sales of the mod hit around $22 million back in March.