Yep. Back in the 90s I used to hit on the VDBs regularly, redeeming vouchers to buy the flight when some hub-attack fare came along against DL in ATL (HNL under $400 was a fave), and the flight bought with the voucher also would be upgrade-eligible and earn miles. Some CO routes back then were highly susceptible. America West tried to say that you couldn't earn miles on flights bought even partially with bump vouchers, but CO would credit them retroactively if you sent in the boarding passes.

As others have pointed out, it happens far less frequently today. And the point about having alternatives scoped out is a good one. One of the really underreported problems with travel today is the combination of full flights and/or lack of interline agreements, especially as far as ULCCs are concerned. NBCNews.com recently did a long story about why flying is so dreary for so many people today, and one thing they pointed out was the multi-day strands from no interline agreements or everything being full. Those will really irritate just about anyone.