Pay-by-weight airfare kinda makes sense.

TODAY’S BIG STORY is an announcement from Samoa Air that it plans to start assessing passengers’ airfare based on their weight.

Here’s how it works: When booking online, you’ll be required to input your weight, which will directly impact the cost of your ticket — “from $1 per kilogram on the airline’s shortest domestic route to about $4.16 per kilogram for travel between Samoa and American Samoa,” according to a post in The Sydney Morning Herald. Then, at the airport, you’ll hop on the scale for confirmation.

“This is the fairest way of traveling,” says a Samoa Air executive. And, from a purely financial standpoint, I’d have to agree.

The fact is, the heavier the plane, the more fuel it burns to get where it’s going. And fuel is expensive. Hence the long-standard policy of overweight baggage fees.

Beyond air travel, you can see this pay-for-what-you-use trend creeping into other industries. Think the end of “unlimited” data plans on mobile devices. Think pay-by-weight yogurt.

Or, consider how we’ve always been charged for utilities. Customers aren’t assessed a one-size-fits-all rate for the privilege of accessing the electrical grid. We pay for however much we use.

Of course, when you step back from the ‘business sense’ of the matter, there are a lot of obvious and emotionally charged arguments against the policy. In equating body weight with mobile data usage, for example, we’re implying the serious health issue of obesity is somehow a conscious lifestyle decision, or otherwise fully under an individual’s control. Which isn’t the case.

There’s also the point to be made that, while the average body type has shifted towards the heavier side of the scale in past decades, the average airline seat has remained pretty much the same size. Also, are we really expecting passengers to submit to doctor’s office-style ‘weighing events’ in the public forum of an airline check-in line?

But despite this carrier’s claim that the initiative will “raise the awareness of weight” among a population who struggles with obesity, no doubt it comes down to the bottom line for Samoa Air. And any other airline that follows its lead. Which, when considering this balance-sheet perspective, will likely happen soon.