That was a good caller

What makes a great caller?  Someone who has first hand experience of the story you are covering.  I produced a show recently where we were talking about Steve Misiura a guy who sat and watched all the 84 episodes of friends - his friend who supplied the videos called in and gave a fascinating insight on Steve what he was like, why he had done it.  He was a good caller, the great caller would have been Steve Misiura but I guess he was sleeping off 84 hours of TV watching. (Left Steve Misiura)