Originally Posted by
Totoro
Standby at the airport is free, so if the flight is wide-open (e.g. 753 that's only 70% filled) you can take a chance.
You're doubling the (minor) risk of a mechanical cancellation, for if either the previous flight or your intended flight mechanicals, you're out of luck. Of course, if you're flying early, you still have your original reservation, which would trump these displaced passengers.