Update: GameStop has indeed sold out, but it's still available on Steam.
I bought a Steam Link just a couple months ago, so it naturally makes sense that it would go on sale for a fraction of what I paid. And I do mean a fraction: the Steam Link is on sale at GameStop for a surprising 90% off, dropping the price from it's usual $49.99 down to a measly $5 (though you'll have to pay shipping and handling as well). If the GameStop link sells out, it's also available direct from Steam.
It's quite a deal for a device that I'm pretty happy with and use semi-regularly to stream my Steam library to my TV. While you're shopping, don't forget to check out the rest of the best Black Friday deals we've found right here.