Gabe Newell ordered to make in-person deposition for Valve v. Wolfire Games lawsuit
(www.gamesindustry.biz)
They used to have a price parity clause in their steam distribution agreement. They loosely enforced it, depending on what game and what service. I think they quietly removed it because I read through the agreement recently and didn't see it but I remember it influencing choices I made for pricing my games on itch.io.