Why did Hewlett Packard stop enclosing return envelopes for ink cartridges? -

The past few ink refills I ve opened for HP ink 74/75 have not had a return envelope for the empty cartridge as per usual. This hardly seems responsible to me. Anyone know what is going on?

HP only encloses return envelopes on cartridges which have aftermarket value. Currently the 74 and 75 have no aftermarket value and haven t for a couple months.