Samoa Air introduced a pricing system based on passengers' weight and their bags this week.
CBS News reported that, depending on the flight, each kilogram would cost 93 cents to $1.06. A man weighing 195 pounds with a 35-pound bag would be charged about $97, CBS reported.
Seth Miller at Fodor's Travel blog noted that although some might argue that charging by weight is unfair, it's "the closest thing the airlines have to charging relative to their actual costs of running flights."
Miller wrote that he doubted the practice would spread through the industry anytime soon.
Norwegian Economist Bharat Bhatta also has proposed a "pay as you weigh" pricing system. Reuters reported that Bhatta believed it would bring health, financial and environmental benefits.
So far, most airlines have limited weight pricing to baggage.