As a European, this bothers me on so many levels. Government should not for one, sell your personal data and furthermore should make sure if it provides access to it, that it isn't used for anything marketing like.
The USPS makes only a few million from selling this data but saves over a billion dollars by avoiding the cost of forwarding mail sent to prior addresses.
The USPS is allowed to do this under an exception for it in the Privacy Act.
If you were renting it's possible your landlord or management company provides information on new residents for 'cost saving offers'.
Worse still, companies such as Experian and Equifax have open access to the full register.
1. Melderegisterauskunft: everyone can ask at the local city government for the current address of a specific person. This isn't free though, it costs (I believe) something about 10-20€ per request.
2. Political parties can get information on electorate: https://www.service-bw.de/leistung/-/sbw/Melderegisterauskun...
3. The GEZ (funding administrators for public television) automatically get all data of persons whenever they move
4. Military gets personal data automatically (we don't have compulsory service anymore, though)