Hit the nail on the Head.

Your Service agreement holds a lot more legal weight than any terms added into a EULA, since you should have had a chance to read the Service agreement before signing upto GoG or Steam, opposed to a EULA which is only made available after purchase (or in the case of Dishonored after installation!)


A Service agreement can be bound to an individual and be non transferable. A software license, under EU and US law due to case precedence is transferable. Thanks to VALVe (and a prior nintendo case) a computer game MAY or MAY NOT be software.

Personally I think the biggest advantage of using Gog instead of steam would be that you are not locked out of not being able to use your game if steam doesn't support a version of Windows. For example steam is going to drop xp support this January. At which point people who still use xp offline will just have no option to play their games in steam unlike gog