It can get really broad, too. A former coworker who used to work for a brand you've probably heard of (if you're American) whose core business model involved/in

It can get really broad, too. A former coworker who used to work for a brand you've probably heard of (if you're American) whose core business model involved/involves a ton of mostly-overnight shipping told me once that he could send a heavy package literally from one corner of the country to another for $LOTS on his own dime, $90 for 5-day ground on the company's dime, or... $8 for early overnight. Eight bucks! I don't think that even paid for the jet fuel. Guess which he chose? Shipping prices are weird.