I wouldn't give their system that much credit -- the belt OP received doesn't even fit the trousers.

    ;laskdfjls;adkfasd;lfj

That incomprehensible line above was written by my advanced AI. Or I was just lazy and wanted to sell something with a cool marketing buzzword, and without regard to ethics.

I thought that at first, but it doesn't make any sense, because:

You don't have any way to know which of the measurements is wrong.

You don't know what correction to apply. The best you can do is shrink along one or more of the dimensions in the direction of a mean of something, which may or may not be relevant to that customer. In return you intentionally mess up the orders of many customers, wasting their time in the process.