F3G - spot on. If it was bad weather and I got a call offering to take my ticket back, I might accept - even if I had been planning to travel. It's a natural extension of VDB, which has been around for years. That means carriers don't have to find some other excuse to break their own rules (which they hate doing as they think it starts a slippery slope) they can just use the process they already have to offer Voluntary Denied Boarding. It's not just win-win but win-win-win: Carrier-1st pax-2nd pax!