Legitimate ways to get more YouTube traffic?

[simon]

As above, we are a relatively new YouTube channel, we are doing fairly well.
We have a few big videos with a few in the thousands of views but for the most part meager views of a couple of hundred.
What is the best way to increase our subscriber base and any other tips gratefully received.
Extra info-
We are adsense approved,
We have a Google plus page that is growing slowly,
We have a Facebook page and Twitter account,
The channel has 186 subscribers so far and 33000 total views.
As said any management tips gratefully received.
http://www.YouTube.com/sic1978 all social links are in banner art at the top of the channel.