To be an effective promoter, you should be able to explain the appeal of whatever you're promoting efficiently. It should fit into a very short "elevator pitch." If you can't do that concisely, it will be very hard for anyone who's not already aware of the subject to understand you or even care. It can't have jargon, only concepts and words any normal person can understand.
Fedora has an elevator pitch that runs fifteen seconds in length. It also has an expanded pitch that is still concise, and consistent with the short version. The expanded version is for use when someone is already interested and wants to hear a little more.
15-second version
Fedora is a collaborative project on the Internet that brings together people from all walks of life to produce and promote free software and content. The project gives away a complete computer operating system that anyone can download, run, study, modify, and give to others.
60-second version
To be worked on