I think the impact on the sales would depend on the type of game. Like he explains in the blog - "it can especially benefit those who make competitive or sandb

I think the impact on the sales would depend on the type of game. Like he explains in the blog - "it can especially benefit those who make competitive or sandbox games. However, for a short, relatively linear experience like ours, for millions of viewers, Let’s Play recordings of our content satisfy their interest and they never go on to interact with the game in the personal way that we intended for it to be experienced. "