Youtube channels are able to be monetised indirectly, eventhough you are not able to monetise directly through Youtube advertising.
Gaining the 1000 subscribers enables adsense, however you are able to make money through the following channels:
Selling physical products
Offering a service (coaching/consulting)
Joint Ventures (affiliates)
There is a whole lot more involved in building up a YouTube channel, I am able to run through this as part of my YouTube building programme.