This is a great marketing move as it tries something that many people who are charged $/£/€/?50+ for an overweight kilogram will have muttered at checkin desks.<p>The truth is that it doesn't work because the bag restrictions are there for reasons unrelated to the weight of passengers.<p>Firstly there's the baggage handlers. Some airports charge the airlines extra for heavier bags so it's a way to discourage a charge to the airline. But far more than that, even in the olden days before most airlines charged for checked baggage, it's a great way to extract additional revenue from the customers in a context of it being the customers' fault.