100% of my travel in 2010 on CO has been on the fabulous E-145...and all EWR-YQB (16 segments no less, all for work).

On 90% of these flights, row 12 has been completely empty, most likely because it's not an elite-heavy route (can you imagine the YQB-based CO PrezPlat?).

Every time boarding has concluded, the f/a suggested to the passengers they could move into row 12. Amazingly, almost no one ever did, except me (CO OP non-elite).

And this was after the implementation of the ELR system.

Obviously, this is a little different than your tale, since no one was ever bumped, but it's interesting to note that the ExpressJet f/a's never hesitated to give these seats away for free, which was great for me.