So posting covers on YouTube seems to be a big deal these days and I'm wondering if any of my fellow coverers have found successful ways to market their channel and reach more people. I've been interacting with other musicians who have covered similar songs and am trying to draw attention to our videos with some friendly networking, but are there other ways to drive up interest in my channel?
Well, it's mostly about posting them pretty frequently and tagging them right. "Justin Bieber" tag works just fine
Work with other musicians, try to network on as many platforms as possible (not just youtube).

As well, you need to be pretty good :-P. If you want to just get popular, you should worry a bit more about your look then your playing, since i think that ends up being a bigger reason to why people end up watching.

For example, look at my signature