Here's a great article from a few years back, by Eric Ries. It breaks down pitches into several types, and examines the key questions that need to be answered by each type of pitch. Worth reading alongside this article, posted a couple of weeks, ago, about startup itch archetypes.
Eric outlines the following pitch types with their relevant "key questions":
- Printing money
- Promising results
- Micro-scale results
- Working product
- Prototype product
- Breakthrough technology
- All-star team
- Good product idea