Nailed it!
Basically we look at the system, and the people who gain lots of Karma in the respective content area (Journalist, Photographer, Producer) start to bubble up on our radar. We look at the specific skills, start to offer support and give pointers. From there if you're doing well, we'll also highlight your pieces so they get more traction - whether that is boosting on social or featuring at the top of the homepage.
Do enough of that, and we pick from this pool to begin writing for us - whether that is the occasional blog piece, Event coverage, Interviews or trip stories.
The system is really what you decide to make of it.