Originally Posted by
IAH-OIL-TRASH
Well it is and isn't.
All airlines will routinely overbook knowing that some will cancel or not show. The practice does allow the airlines to sell more schedule opportunities to passengers and protects them from always going out with some empty seats. Most of the time it works out, but often, IDBs occur. I can understand UA not wanting to increase the potential for IDB liability by giving out a free ticket after a flight has been sold out. IDB compensation comes out of revenue and there's no point in issuing an award ticket if that very fact cause an additional IDB payout.
The award ticket is cashless but in no sense of the word "free" either to the passenger who paid for the miles (one way or another) nor from UA's perspective, since they retire the liability associated with those miles.
I can see us getting into a debate on "what is a seat?" (an actual seat on the map? the difference between seat count and reservations? the difference between seat count and statistically expected pax to show up?) but in my view this is a limitation on what is billed as unlimited benefit and distinctly not flyer friendly.