The bad news is that there will be a lot of competition: every indie filmmaker with any marketing savvy has already put up a trailer or promotional clip for their film on YouTube. The good news is that YouTube operates by the same rules as any search engine – and you can use Search Engine Optimization techniques to your advantage.
In addition to allowing you to tag your videos with relevant keywords, YouTube indexes the text in video descriptions. A description can be as brief as a single sentence synopsis – but it can be so much more! YouTube doesn’t limit the length too strictly: you are given 5,000 characters to work with. By filling your description with keywords, you can make sure your video doesn’t get lost in the sea of millions of others.
If your strategy doesn’t seem to be working for you, YouTube offers an excellent analytics tool for gauging your viewer data. Tweak your strategy accordingly, and see if it pays off!