Epic's Grand Theft Auto 5 giveaway in May was so popular that it broke the Epic Games Store: the demand was so high that it caused a variety of problems, from unusually chilly to inaccessible for an entire day. It also capped off four major game giveaways that pushed the Epic Games Store's concurrent user peak close to that of Steam.

GTA5, Civilization 6, Borderlands: GTA5, followed by Civilization 6, Borderlands: The Handsome Collection, and (after an unexpected delay) Ark: Survival Evolved. The giveaways constituted a "user acquisition campaign" known as The Vault, reflecting the fact that, unlike Epic's other free campaigns, the giveaways were hidden behind images of a large vault door until the giveaways began. The campaign was a huge success, with the Epic Games Store averaging 13 million concurrent users at its peak and over 61 million monthly active users, Epic announced today

. [Since launching the Epic Games Store, we've always wanted to build around our highly successful free game of the week program and host a major event that offers something great for players around the world. We're very excited to be a part of this," said Steve Allison, GM of the Epic Games Store, "and we're excited to be a part of it.

"In 2020, we are experiencing historic growth, with Epic Games Store partners having a huge audience of players who can sell their games and receive 88% of the revenue instead of only 70% like other platforms. We are very pleased with the results."

While 13 million concurrent users at peak is a far cry from Steam's record of 24.5 million (and nearly 95 million monthly active users in 2019), it's enough to put the Epic Games Store in Steam's off-peak trough. This may not sound like much, but it shows that EGS is a viable storefront for developers and publishers that can attract a significant audience (beyond Epic's exclusivity deal) and thus gives them a reason to commit.

It is also a significant accomplishment for a storefront that has been in existence for less than two years: as Epic CEO Tim Sweeney said in an interview earlier this month, storefronts like Humble and GOG are launching with more features than EGS. and spent years achieving just 1 percent of Steam's market share.