The ZIP code system in the US CAN somewhat work the same way.
The usual 5 digit ZIP code routes to your Post Office. The longer ZIP+4 code routes more detailed locations: a city block, an apartment building. The even longer ZIP+6 code goes to something called delivery point, which to my understanding is basically a single mailbox. The ZIP+6 code is in fact embedded in the bar code sprayed onto the mail piece.
Though you might have missed the concept that it follows you if you move, I think?
If there was a zip code that was just virtual PO Boxes, it could use the existing change of address machinery to slap the actual delivery address on when addressed with a virtual box. Assuming they used an entire sectional center facility for it, you could have 100 zip codes, with 6 digits of unique delivery points, so 100 million virtual boxes.
he said "somewhat work the same way". For a person who doesn't care about whether they have to get a new code when they move, the systems are equivalent in their value proposition. Thus is the case for most things that "somewhat work the same way".