DrewE wrote:

It's mainly a vacuum because this is a sort of hybrid delivery service: UPS (or whomever it was) ships it most of the way, and then turns it over to the USPS for local delivery. Your tracking number is just for the USPS part of that process. Since the local delivery part happens very quickly, possibly just from your local post office to your mailbox, and USPS updates their tracking info relatively infrequently, you don't get much useful information. Doubtless UPS is internally tracking the shipment through their systems for the first part of its journey, but alas you don't have access to that with the USPS tracking number.

If you (or the company you were buying from) wanted shipping with more complete tracking information, they could choose a less inexpensive shipping option, e.g. one where the shipper themselves delivered the parcel to your door.