I think you're really underestimating Let's Players here... they are a big factor to a lot of people. If the Game Grumps play something you can expect the fanbase to buy plenty of copies.
Those huge companies don't need them sure, they have plenty of money to advertise. But it's definitely a boost when everyone on youtube is making your game look like a blast to play versus an ad that's obviously bias. Even Microsoft who was opposed to Let's Plays has caught on that they're beneficial.
I know that I've been convinced to try certain AAA titles because of Let's Players and certainly not the advertisements.
Those huge companies don't need them sure, they have plenty of money to advertise. But it's definitely a boost when everyone on youtube is making your game look like a blast to play versus an ad that's obviously bias. Even Microsoft who was opposed to Let's Plays has caught on that they're beneficial.
I know that I've been convinced to try certain AAA titles because of Let's Players and certainly not the advertisements.