Epic Games Store is offering developers 100% of revenue for six months of exclusivity
(www.videogameschronicle.com)
I 100000% believe your comment on the pre-existing library is why they give free games away weekly. They want you to build a library that you then won't want to move from which is exactly why I too don't like being forced to buy things on another game store. I don't like exclusives no matter where they are, it's anticompetitive bullshit.