Right now I'm lying around 5000 views a day, the way I did it (and still do it) Is that I reply to all comments.
Yes of course delete/ignore/block people who are trolling and/or flaming, but involve your audience and connect with them.
Of course when you get to this point, not all of them will show in notifications, however I still try check many times a day, and I look at individual videos everyday too.
Another thing (which I started VERY recently) is to make a fan-page on facebook, and have a Twitter. That's mostly for mid-large channels about 5000 subs or more, that means you can get an active following on Facebook and Twitter resulting in more views.
The third tip is what has worked best for me, and it may sound simple but I will go into deeper detail. Get your videos semi-viral.
Now everyone says "If I could I would, but I can't so I shan't" however you CAN do it, make videos which alot of people could find funny, have good quality video/audio, possibly something no longer than 2 minutes, make sure it catches people in the first 10 seconds.