Grargar: Not content with merely timed exclusives, Epic takes it to the next level by acquiring Psyonix, the developers of Rocket League, one of Steam's consistent top-sellers for the last 4 years. As a result, the formerly Steam-exclusive game will be removed from the store and become an Epic-exclusive by the end of the year:
I'm pretty sure effectively gutting the multiplayer community of a multiplayer game is a death sentence. It wouldn't surprise me if Epic would sacrifice Rocket League just to spite Steam. That said there was an announcement that there are no plans to remove the game from Steam - wouldn't surprise me if Epic goes back on their word though.
Meanwhile, another Epic-exclusive, World War Z, sells around 250k copies on PC in one week, with the developers attributing the success to the Epic Store support:
Link 1 Link 2 I'm curious about Valve's counterplan (if they have one).
An odd note:
"What surprises us is the fact that sales outside of the U.S. on the Epic Store have been so strong, with the U.S. being only one quarter of sales."
I suspect that if the game was released on Steam that US sales would be a lot higher. My guess is that Steam will wait for the exculsivity period to end and see how well they sell on Steam. If those games sell like hotcakes on Steam my guess is that Steam will do nothing - let your competitor destroy his own capital by offering pointless exclusives, there would be no point in interfering in that business model if that were the case.
If those games don't sell well I'm not sure what Valve can do - most responses I can think of could get Valve in trouble violating various anti-trust laws which Epic would undoubtedly pounce on. Epic has the advantage here since it's much smaller than Valve after all.