SimonG: GOGs DRM free policy was extremely successful marketing. When they started they sold mostly DOSBox titles which are impossible to DRM.
Well technically it's perfectly possible to add all the DRMs you want to DOSBox games; GPL (especially the one used by DOSBox) doesn't forbid DRMs, you need to provide full source code of everything you do but it would be perfectly possible to do an open source DRM. (Of course that might create a shitstorm but that's another story)
SimonG: But GOG wasn't founded to further some "DRM free revolution", it was founded to make money. But that isn't a bad thing. Quite the contrary.
But that's actually kind of the point: of course they are here to make money like any other company, but what's important is HOW they do it.
If a company want to make money by releasing DRM-free games, release all DLC and major upgrade of one of their big budget game for free, etc... then great, even if it's only because they are "greedy" and want my money, I am perfectly fine with it and I will gladly give it to them :) .
Having worked, directly or indirectly, for several big companies, I am perfectly aware that for most of the things they do, good, bad or ugly, there is a "valid" reason (often valid in a very twisted and cynical kind of way) behind it, but it doesn't matter as a customer I care only about
what they do... not
why they do it.