I'm not entitled to give you numbers, but this is a heavily practiced strategy in game development.
Developers will go as far as pretend their community manager is a regular user with his own channel though most are open about it.
Even better, they encourage networking and users to start their own fan channels.
The idea here is that you always need to be there to start your own community, else no one else will (most of the time).

You don't necessarily need comments on your videos (most turn out into flame wars anyway) but you should definitely have traffic.
I'll let it up to you to determine how you'll acquire users for your channel.