You mean the publisher?
PCGaming
Rule 0: Be civil
Rule #1: No spam, porn, or facilitating piracy
Rule #2: No advertisements
Rule #3: No memes, PCMR language, or low-effort posts/comments
Rule #4: No tech support or game help questions
Rule #5: No questions about building/buying computers, hardware, peripherals, furniture, etc.
Rule #6: No game suggestions, friend requests, surveys, or begging.
Rule #7: No Let's Plays, streams, highlight reels/montages, random videos or shorts
Rule #8: No off-topic posts/comments
Rule #9: Use the original source, no editorialized titles, no duplicates
I'd expect EGS exclusivity to be the norm then. People who will buy the game eventually will buy the game eventually. Those are fixed sales since they'd get the same revenue from them either way. It's just a breakdown of the sales lost from people refusing to buy the game ever outweighs the 30% you gain. Which at this point it seems like a ridiculous proposal since every game seems to launch to bigger and bigger numbers regardless of what bullshit the game pulls. People who wait for sales would barely matter since a steam sale is like a year after release and they weren't making bank on them anyways.
But at face value, getting 70% of one Steam sale is only 10% more than you'd make off two copies sold at 100%. So one "never buy" looses you 2.3 sales of a game in revenue. Cool but any converted sale from someone who wouldve bought on Steam but can't wait and buys on EGS offset that in favor of EGS. I guarantee more people will buy from EGS compared to never buying the game. 2.3x more? Yeah, for sure, lol. I'm sure someone could do some clown math for a break even point per 1 million sales at that point. But considering a bulk of a games purchase is at launch it's just skewed so heavily toward EGS exclusivity makes more financial sense.
There's also the percentage that just don't buy on PC and buy on console instead, but again that's the same cut you'd get just launching it on Steam
Is this in lieu of an insentive payout up front or is it supplementary to one? If this is supplementary to an upfront payout I could see how it'd be worth it for a small dev. But if you don't get that payout up front for exclusivity I can't see how this would make any sense. I can't imagine EGS sales amount to much compared to what you'd get from a steam release; even with 100% revenue.