Ancient-Red-Dragon: That would be a waste of GOG's money, because no one likes when people shill, and what you are asking for would be youtubers to shill for GOG. That will turn people off from GOG, not bring in new customers.
I do agree that GOG should try to advertise better and market more, if possible...but paid sponsorship shilling is not the right way to do it.
On the other hand, if GOG could convince some youtubers to promote them for free, on the basis of the youtuber(s)' genuine real interest in the principle of DRM-free, then that would be another matter entirely, and that
would be something that is worth GOG pursuing.
AB2012: Well
they used to, kinda... :-)
Ancient-Red-Dragon: Someone needs to archive videos like this. Chances are, GOG will order videos like this to be deleted off of their official channel eventually since their flip-flopping into the dark side makes them look really bad in light of how their own videos call them out for their own future bad behavior (i.e. embracing the "regional pricing" scam).
I doubt that many Youtubers would be willing to do free sponsorships. They are a business just like any other, so most of them require payment for their services. Keep in mind that YouTube sponsorships are really not that expensive. It generally costs between $1000 to $10,000 per video (depending on the channel), which is relatively cheap for what you're getting. Sometimes you can get millions of views for each video, so it can often be well worth the cost. There's absolutely nothing wrong with supporting content creators in this way, since the deal would benefit GOG and the gaming community at the same time. This would be a quick and easy way for GOG to get some traffic, especially when it's marketed directly towards their key demographic.