Obesity & air travel

Two stories caught my eye last week - both about obesity and flying - or were they? One was about passenger weight and the other was about airplane seat width, but what were they trying to address and will they achieve their aim?
'Pay-as-you-weigh'
At the start of April 2013, Samoa Air introduced 'pay-as-you-weigh' pricing for their airline. They argued that "a kilo is a kilo" when it comes to car...