I am from DC but used to live in Miami. Coming back to MIA on a Sunday night, I flew to Tampa and then onto MIA on a prop commuter (US Airways). When scheduling, it was the lowest fare so I accepted that odd route. The commuter flight was oversold so I took the bump and got the free ticket. Took another flight an hour and a half later. The agent told me that my original flight was "almost always" oversold. I used the free ticket to go back to DC a few weeks later and requested the same DCA-Tampa-MIA flights for my return. Once again. I got bumped. Took the free ticket. I repeated the process again the next month. Got bumped. It worked again!!! My discounted $190 r/t to DC on my original ticket netted me three additional r/t's!!! Further, I was able to upgrade the DC-TPA segment each time with upgrade certificates! Moral of the story: If you want to get bumped, and you've got the time, find those flights you know will be heavily booked, get there early, smile, and offer your seat to the agent.