People think of Youtube as a place to watch videos but just like any of the other social networking sites there are plenty of ways to interact with other users and engage with the community. You'll need to start befriending people within your niche, sending them private messages and complimenting them on their own videos and leaving comments wherever relevant. This is a slow process and is very similar to leaving comments on other blogs to grow blog traffic and although it takes lots of time it is highly effective and is a great Youtube view booster.