As with many air travellers, I have in the past been forced to share a significant fraction of my seat with parts of my overflowing neighbour. As a result, I can only applaud Samoa Air's move to charge passengers by weight:
Air Samoa's rates range from $1 (65p) to around $4.16 per kilogram. Passengers pay for the combined weight of themselves and their baggage.Samoans are famously large, ranking number 2 in the world for fraction of adults overweight. Air Samoa operates small and medium-sized planes where passenger weight is a substantial fraction of the aircraft, so they are in the top right corner of special cases. It will therefore be extremely interesting to see how this plays out.
I would expect there to be an immediate flow of heavy or luggage-laden passengers from Air Samoa to other airlines on the same routes. In parallel, of course, lighter and luggage-light passengers and families with small children would probably find Air Samoa a more competitive fare. As the cabin composition changes and the mass of passengers relative to space, it's quite possible that Air Samoa will find itself having to charge a minimum price per seat to cover its costs. Other airlines will be looking very carefully at the results - you can just imagine o'Leary of RyanAir salivating at the opportunity to offer prices "£5* to Dublin return!" with the caveat in 2 point text "(*) for passengers weighing 10lb and under".
If this spreads more widely, to the point where passengers on certain routes have no choice but to pay by weight, I can see several consequences. One is that the airport loos next to the check-in desk will be much more heavily used. Perhaps they'll need to charge £1 per person entrance as a result. Airport food will become more expensive as it becomes more expensive to check-in with food on your person or in your baggage. I wonder if airlines will need to re-check weights just before passengers board, in case they leave the heavy contents of their hand luggage with a friend before they check-in and then re-pack the bag before going through security. It's all going to be vastly entertaining.
Soon enough, surely, some large gentleman is going to sue the airlines claiming that they are (price-) discriminating against him based on his medical condition causing him to be overweight. I have no idea which way this claim is going to go, but I'm fairly sure the lawyers will get substantial fees in any case.
Still, if it means that I don't have the large rolls of fat from Mr. Smith billowing over the seat handle into my lap, I look forward to other airlines adopting this pricing technique post-haste.