Jorev: How much are the people streaming on GoG's Twitch channel paid for doing that?
Twitch pays approximately 50% of sub revenue to streamers who are affiliates or partners on the platform. The actual amount a given streamer receives may be less than that due to currency exchange and/or transaction fees. In addition taxes may be withheld depending on the country and whether there is a tax treaty in place with the USA.
In addition any "bits" that people spend on Twitch are essentially tips to the streamer, where 1 bit is 1 cent, 100 bits is $1, etc. and the streamer receives all of that money.
Ad revenue on Twitch is basically irrelevant as Twitch pays out so little for advertising that even streamers that have hundreds or thousands of viewers end up making only a few dollars a month at best from ads so ad revenue can basically be ignored. As an example I know at least 2 streamers who stream 4 days a week, one with an average of about 65 viewers and another with an average of about 250 viewers. The first one made about $3.50 the month he test-ran ads as a partner and the second one made about $7 in a month. So, basically ads are useless.
Many streamers also have a StreamLabs or StreamElements link with which people can tip them directly in cash and they keep all of that money minus the PayPal or Payoneer or whatever processing fees.
Some streamers also use Patreon which has different payouts depending on when one's account was made, but pays out an average of about 90% of the revenue from subscriptions (more or less depending on when your account was made).
These are all "in general" for Twitch streamers as a whole. GOG states that they divide the revenue they get between all of their active stream team, so whatever monetization methods from above are on the channel will be split across the team basically.
It's impossible to know exactly how much money that is as it is not public information other than anything that the given streamers publish on their stream overlays.
The majority of streamers on the Twitch platform do not make very much money at all (gaming or otherwise) and that is probably true for those on the GOG stream team also. It's more of a passion for gaming and the bragging rights to be on GOG's team than it is about money I imagine. Plus it is a way for them to kind of advertise their own streams, the time they spend on GOG's stream acting as a way for them to gain new followers for their own streams, and naturally some of those people will translate into the streamer's own subscribers/tippers/etc.
Ultimately though, unless one of the GOG streamers publicly tells people how much money they make from being on the team, there is no way to know.