When you're introducing a new idea, its easy to get wrapped up in its details. You may be justifiably excited about exactly how your idea works, but details make for bad communication. You need to get people hooked. Hooked people will demand the details so they can share your excitement.
Hook people with an analogy. Reduce your idea to two concepts your audience understands, then announce your idea as a new combination of those two concepts.
People pitching new movies to film studios use analogies. Which interests you most: 'cartoon follows a dog with an identity crisis journeying across the country' or 'the Truman Show meets Homeward Bound'? Describing the movie Bolt, the second phrase is more effective. The description is boring. The analogy prompts questions: does the out-of-place guy go across the country or is it a dog that thinks he's something he's not? Questions mean you've landed the audience. Giving people a place to put your idea (the intersection between the points of your analogy) lets them care about your details.
A recent software release got this right. Voice Candy is an audio editor for Macs.
Mac users know Photo Booth (its fun!) and everyone knows what a microphone is. After reading this short description, I want to learn all about this new program: does it warp my voice? can I sound like darth vader? By introducing their software with a relevant analogy, Voice Candy's publishers are intriguing us into learning more and buying it.
If your pitch is confusing, try framing it with an analogy. We're the x for y. If your audience is familiar with both x and y, they'll understand what you are trying to do. Everyone needs a place in which to put your idea, giving it to them helps them understand. Good communicators serve their audiences.