&quot;Amazon seems to represent less than 10% of packages in the US [1]&quot;<p>No.
They represent &lt;10% of <i>revenue</i> for UPS, as the cite says.<p>That gives you no info about the percent of packages for UPS, despite the quora claim.   It&#x27;s not safe to assume they pay what others pay, and in fact, given the range of volume discounts, it&#x27;s entirely possible they pay 1&#x2F;3rd-1&#x2F;5th what others pay, if not less.  (I base this on the fact that the companies i&#x27;ve worked for, which have nowhere near amazon&#x27;s volume, seem to pay around that). If that was correct, they could represent 5-6% of revenues but 15-25% of volume.<p>(it also tells you nothing about overall. It could be that combined across 6+ carriers, they represent a large percent of all package volume in the US).