Got This Piece Recently In The Mail?

I got this piece of mail recently in the mail delivered by USPS. The label states that is went through DHL Global Mail. Don't know all the particulars but it looks like DHL handles everything till it gets to the local area and then the USPS gets it there the rest of the way.
I don't know what agreements DHL has with USPS or other postal systems but can someone really get cheaper delivery service than if they went straight USPS?

Yes! UPS and FedEx does more or less the same thing, the theory being that it is cheaper for the USPS (who already has the framework in place to deliver to every address in the US) to take the packages to their intended destination than it would be for these private companies to spend their resources to do it.

This excerpt is taken from Wiki:

UPS/Fedex/DHL often use the USPS for the final leg of the journey, particularly for addresses that might be off the beaten path of their normal route, such as rural address and smaller towns, etc. The USPS has a somewhat symbiotic relationship with some of their competitors this way.

I often get things that I ordered through Amazon via the UPS to USPS route. Funny cuz my UPS driver is by here daily.