Michael at 2011-11-08 18:15:57:
I believe it comes down to is the passion and plea of the pitch. You have to believe in your story.
Here's a short story:
I was an intern at a busy commercial/music video company that frequently hired freelancers for work. After building a rapport with one of these freelancers I pitched an idea for an over the top short film I wrote about high school. The pitch went well and the guy asked to see the script. Later that week I had 4 copies of the script with notes on it from other freelancers I worked with.
Essentially what it comes down to is believing your story is good, and communicating the key parts of that story in an entertaining way.