Random thought for reviving Post Office revenues

Image by Jeremy Burgin via FlickrYou know how, whenever you order something, you get reminded that the Post Office won't let UPS and other private package services deliver items sent to PO Boxes?

Now that the revenue plunge at the Post Office is so bad that they're thinking of killing Saturday deliveries, maybe there's an opportunity there . . .

Why doesn't the Post Office simply accept all deliveries from UPS et al. slated for PO Boxes for a 10% surcharge on the shipping? It would end up being fed back to the PO Box customers, who would then find their PO Box address even more valuable (and create a revenue boost for the Post Office).

Wouldn't be huge -- but wouldn't every little bit help?