This is from Marketing 101. Whatever it is you're trying to sell and no matter who you're trying to sell it to, you need to have a short description of your product or service that highlights the best features you have to offer. The term "Elevator Pitch" comes from the the amount of time you would have were you to share an elevator ride with a prospective client. Fifteen seconds would be the maximum time, and even then, its a long ride.

Here's and example:
 
HungryVermont.com is Restaurant Search Engine for the State of Vermont. We offer restaurants free listings and control over their information. Paying Restaurants get top placement in our search results and also get searchable menu items, which can be updated at will with our Menu Management System.