Will assume you refer to pitching / sales conversation.
The worst you can do in sales is talk a lot (a good rule is talking 20% of the time, maximum).
I'd recommend:
- writing down the types of customers you might have (user personae)
- capturing the value you offer to each segment in 1 sentence.
Let's take Facebook example:
For users: Connect 24/7 with your friends
For businesses: Sell products to your target in a clic!
For game developers: Push your apps to the biggest pool of players.
For media: Your content introduced to up to 1.7 billion people worldwide...
For investors: Get great ROI on a growing product the whole world is using.
A first conversation should spark interest.
Then, you can ask questions and go on to features / details.
It's very hard to be concise, you might fear leaving some advantages of your product out, and it takes a lot of work and market feedback to make a short pitch right ...
A little story-telling + 'help' section would be great to onboard new players.
A share button, for twitter + facebook where with a description (where the cool story-telling could play a part).