[Zaiken]

You can usually post a good video which is informative and share it on Twitter using tags. And then buy real retweets.

It depends on what type of gameplay you're uploading. If your content is not unique or styled like 2010, then don't expect it to get a lot of audience.
For advertising, consider posting your channel links regularly to social networks like Twitter, Facebook and even Google+!

I always post the links to Facebook.

Only your friends and family are likely to see that.