He's not trying to bribe anyone. Just in case you did not understand the point of giveaways :
People do giveaways to bring atention to their stream/channel. People that join there will mostly check his videos or stream for a while and may end up liking what they see or not.
It's like ofering free food on a live show. People will mostly go for the food but they may end up liking the show and come back again.
Not particularly... I agree that it gets more people viewing a channel, but making people Subscribe so they can get a game... It is different. If you want to use an example it is like filling out one of these bullshit surveys online to get something. You are tied into it that way even if you don't want to be...
Plus I have seen a shit tonne of "Giveaways" on these Forums. I have seen Zero that are legit.