Once I discovered after boarding a flight to Washington DC for a meeting that the person handling my reservation had sent me a confirmation but the hotel never accepted the reservation as they were completely full, as were virtually all other hotels in town. I got stuck in some awful place well out the suburbs and had the pleasure of getting into town during a particularly bad rush hour as it had snowed that night. Not fun....and no Super Bowl (or Ryder Cup or Final Four etc.) either. [In fact, it's not unusual for not only all Starwoods in Minnesota to be fully booked, but also all other downtown hotels. In these case, I don't know what people do as sleeping on the streets can be fatal during our winters.] I've also seen hotel space be very tight in major cities such as SF, Philadelphia, Vegas (of course), New Orleans, Atlanta, San Diego, Chicago, NYC, Paris, London, Tokyo, Singapore, etc.