There are pros and cons to the different business models, but in this case, if you think of it as a matching/sorting type of problem, it's inefficient and waste

There are pros and cons to the different business models, but in this case, if you think of it as a matching/sorting type of problem, it's inefficient and wasteful, in a logistical/Nash equilibrium sort of way. Which doesn't always mean it's the wrong way, from a business perspective. But if you're charging by height, it's leaving money on the table.