Just did a GOG survey that focused on the idea of a paid membership option on GOG. Seems they're determining what people would be willing to pay extra for. Some of the options were
- a tool for backing up offline installers
- ability to install previous versions of a game
- extra insight into the preservation work they're doing.
- voting rights on games to bring into the preservation program.
And others that I can't remember.
I filled the survey as well. It's mostly focused on "games preservation". I'm not up to pay subscription for anything they're willing to offer and even made sure to tell them that I'm willing to pay a premium for whatever useful content (games) end up exclusive to subscribers