Not just sharing a game, but sharing a library of games, Steam announces plans for a Family Sharing scheme that accomodates up to ten different computers.
The scheme is intended for close friends and family members, allowing them to play each others' Steam games without having to share the same account details.
"Once a device is authorized, the lender's library of Steam games becomes available for others on the machine to access, download, and play," explained Valve in a prepared statement.
"Though simultaneous usage of an account's library is not allowed, the lender may always access and play his games at any time. If he decides to start playing when a friend is borrowing one of his games, the friend will be given a few minutes to either purchase the game or quit playing."
An official beta group is welcoming new members, and 1,000 of them will then be selected for participation in the first Family Sharing beta starting next week.
A public test version of Steam was launched on September 12, 2003, as a way of keeping players' games up to date: specifically, an online multiplayer game called "Counter-Strike 1.6" which required each participant to run the latest revision of the title.
Only by November 2004 did Valve give Steam a serious push, making online registration mandatory for all PC copies of the new, widely anticipated, and critically lauded "Half-Life 2," turning its update service into a copy-protection scheme that had advantages for both players and publishers.
Since then, its reputation has been forged on convenience and huge annual cut-price sales. Company co-founder and current Managing Director Gabe Newell now has an estimated net worth of $1.1bn.
Discount-oriented services such as the Humble Bundle, Indie Gala and Indie Royale have sprung up in response; publishers such as Electronic Arts, Ubisoft, Paradox Interactive, CD Projekt Red, Sony and Microsoft have launched their own digital distribution platforms.
And generous though the ten computer limit may be, restricting the Family Sharing Beta to entire libraries rather than individual titles obstructs the use of timeshare accounts between groups of friends, or between entrepreneurs and bargain-hunting customers.