Hello all, this is my first post here.. congratulations on this informative and entertaining forum 
To all of you who have built quite a track record of licensing your images over and over: how has the frequency changed throughout the years? Did your images grow in demand from the time you first sold them? Or did you experience an initial peak in requests which quickly faded?
How do these patterns differ based on subject? I would assume journalism and other event photography generally has quite a rapid fall into oblivion, while more abstract, historic or artistic shots tend to maintain their value a long time, if not increase in value.

