Someone asked me that recently. It’s a question no one has ever asked me in the almost-25 years I’ve been studying the history and development of Black American mass media (e.g., Black radio, Black newspapers, etc.).
Here was my answer ((c) 2015 by Todd Steven Burroughs, all rights reserved. ;)):
1) Availability. You must be one of the people. They must be able to reach out to you and see that you are living with them, facing the same problems, etc.
2) Integrity. The audience must see/hear/read (that) you stand up for the interests of Black people unapologetically. You must be for Black people first and last.
3) Ubiquitousness and Longevity. The audience must see you as a permanent part of their lives, like a public utility. And you must be consistently THERE for years, if not decades.
That’s really about it!
AUGUST 2015 UPDATE: And THANKS to Ebony for printing a truncated version of this in the display box of its August 2015 issue!