"Are the most succesful photogs in the Microstock field exclusive - No, why do you think that is?"

This is debatable. Very debatable. Lise Gagne and "Hidesy" and probably a select few more are exclusive and could perhaps be considered more successful than Yuri Arcurs or Andres Rodrigues. It really depends on the total information being given.

From my point of view, I'd like to see exclusivity, maybe not right now, but very soon may be an option.