Here's an interesting comparison of good and bad pitches in a specific context, that also applies to other context. By Andrew Peek:
My recommendation for any startup reading this, is to shift your mindset ever so slightly. Prepare like you would, but when you walk in that door, have a 4 or 5 minute story to tell, instead of 25 answers to 25 commonly asked questions. In fact, take this approach on every occasion where you get to pitch your business.
The next time someone asks you, "So what does your startup do?", lay it on thick. Tell a story. Get them to empathize.