One more thought on where these might come in handy - if you or your business are the destination of lots of travelers these might be handy. A replacement bag would be a nice gesture from a nice hotel or be nice in an office full of travelers back and forth.

But really, I think the intent of these boxes is not to be used as carry ons, but to replace luggage and send them through a package service. The fact that they are luggage shaped is just a convenience. The economics of this is questionable for most. Though my very eldery next door neighbor would UPS her luggage when she traveled because of the door-to-door convenience. Carrying a purse to the airport, etc... was all she would manage. She would have saved lots of shipping costs using these instead of actual luggage.
See, e.g.
http://www.theupsstore.com/products-...e-Box-Info.pdf
http://www.dailyfinance.com/2010/06/...rline-baggage/