Below is the screencast for a presentation I gave at the
Sacramento Drupal Users Group on Saint Patrick's Day 2010, titled "Drupal as a profession". (I apologize ahead of time for my lack of public speaking skills, hopefully you'll find this information helpful in spite of this!)
UPDATE: I highly recommend listening to
this presentation given at Drupalcon San Francisco in addition to my presentation above: "YOU SHALL NOT PASS: Managing Expectations and Boundaries of Clients"