I don't know if this constitutes "selling data", but the USPS allows you to run direct mail campaigns on routes and neighborhoods. The USPS provides moderately granular, aggregate data about the route/area, which you can then target. Some of the data includes household income, household size, and age brackets. Insofar that I know, you cannot unsubscribe from this type of mail.

You can see for yourself here: https://eddm.usps.com/eddm/select-routes.htm