I bet continental.com doesn't do this (allow cancellations within 24 hours) out of the goodness of its heart. They do it because they are constantly monitoring bookings to do anything they possibly can to get a handle on demand for particular flights, destinations and times of day.

So the fact that someone is interested in a particular flight is valuable information to them, even if that person winds up canceling.

After all, figuring out what flights are in demand, and making good predictions so they can boost fares accordingly and selectively is a big part of how they eke out a bit more profit on their generally slim profit margins on selling a seat.