A lot of other necessitites had to be manufactured, which is where Morty fit in: He rose from worker to management in one of Mortality's many factories, one that made straight razors. He lived what he considered to be a normal life: An honest day's wages for an honest day's work.
Until his reflection reached out and strangled him to death, in voliation of everything he thought he knew.
But he lived on... Sort of. Morty had been strangled by the reflection of the mirror next to his bed, while he was flipping through his journal. Now, anyone who picks up the journal -- the leather book -- becomes Morty, through poorly-understood transdimensional means. They have all of Morty's memories up to his death, plus possibly a few hours or days memories more, as experienced from the moment they became Morty.
Morty is sure to write important things down in the journal, as every so often the memory resets back to the moment of his death. He can't seem to maintain new memories in a new body for long. Once the journal removed from a body, the body regains its old memories at the next Backup, regardless of whether the person participates in the Backup system or not..
Over time, the journal has been modified. It is now capable of growing new pages (which is good, since many are ripped out), and has a built-in camera in the eyes, for taking pictures which appear on the pages of the journal. It also has been known to interfere with the local backup sytems in a strange way, completely independant of wishes of the current "incarnation" of Morty. Plus, when Morty owned the journal in Mortality, it didn't have a face...
The journal broadcasts its contents periodically via radio.