GOG should do the same as "Flippfly" with the game "Race the Sun". GOG sell the game WITH A CODE, the user go to website of the developer and insert the code. Result: The user have the linux version from the developer (and the support too).
Easy and simple.
Purchased Race the Sun here, played it a lot and then sometime later redeemed my Flippfly serial.
Now I have it running (beta) on Ubuntu like a beaut too.
Humble Store introduced a dumb idea of regional pricing. GOG has a clear advantage here, but you need to roll out Linux support really. Then you'll have both advantages.
That Humble place has been getting worse and worse but at least there's Linux support.
Yeah, that's annoying
But ''developers can manually set their own pricing for different regions if they wish.''