[cperciva]

Oh, and there were several empty seats on the flight.

Which just means that some people bought tickets and didn't turn up (and that there wasn't anyone on standby for that flight).

Airlines can't win: If they overbook flights, people complain about being kicked off; if they don't overbook flights, people complain about how there were empty seats even though they were told there were no tickets available.

[TheSOB88]

Didn't he just say Travelocity owned the tickets? If the airline's not directing the stranders to where they can actually buy flights (or the flights are too expensive on e.g. Travelocity), there will be empty seats.