To all, the answer is, "It depends".
1) The biggest idea first off is that Net Neutrality eliminates the ability for consumer internet providers to allow preferential treatment towards services or increase charges based on web demand and data usage. A big example is say, Youtube, Twitch, your local internet adult video website. Any of these websites involve either streaming or video use, which is a major drain on data and web resources. Under the law, these had to be treated equally to someone's blog page written in the most basic programming language and amounting to less than a megabyte of text and script.
With the law repealed, this means that web providers are given much more freedom. Example, Google owns youtube, and devote additional resources to Youtube while denying them to other web services like Twitch. (Yes, Google has an internet service, but it's very limited right now). Twitch can demand the same treatment, but Google might say Twitch has to pay for it. Or, Comcast decides they want to promote their own web streaming service, and denies twitch and youtube, or blocks access all together without an additional fee from the consumer to access, similar to something like having HBO or CInemax on television services.
However, this is all speculation. The possibilities are only limited by however the company can think to exploit them, and however they can manage to do so without a full revolt of their consumers. I'll explain this more later. As far as GoG is concerned, it might see no difference, or it might be regulated to slower downloading speeds because it's a service that provides large downloads of digital products to a wide audience. The same would probably happen to Steam, given the audience size and amount of product. Again, this would be up to the internet provider.
2) Again, it's somewhat speculative. GOG is popular in our community and has been growing in size for a while. As far as pure market share, it's impossible to say both because of users having both services, and potentially having the same products on each as well. Digital sales are also generally not recorded by volume, or they weren't for a long time. If you look at console best seller lists, those lists are always made on a basis of physical only sales, because it's easier to measure product being shipped than product via web traffic. I don't know how much this has changed, but in terms of impact, the end result is "it doesn't matter", because any impact at all is inherently bad, regardless of how much it changes. Whether it means someone in a rural town isn't allowed to download as fast as normally, or someone is denied access outright, it's ultimately an unfair situation.
3) This depends on numerous factors, but I think ultimately it won't really effect international users. GOG does have a massive United States userbase, but I believe has most of it's utility and services in Europe. If European utility companies operate on the same law as the United States did two weeks ago, the changes might encourage them to pursue an end to net neutrality too. If they operate by the way the utility companies are now in the U.S, they have no reason to change. I'm assuming the latter is not the case. And even if a company owns Utility in both the US and internationally, they have to follow the guidelines of that specific country.
In short, it's really all a large confusing mess with a large number of possible outcomes, but really it hurts U.S. Consumers more than anyone else (Potentially) and might lead to possible repercussions elsewhere. This all is assuming that Net Neutrality isn't held in place by a lawsuit for several years by the NUMEROUS amount of agencies and states that are currently planning a joint suit against the FCC.
Post edited December 16, 2017 by QC