Anti-virus protection, like Norton, has to be updated every year to keep up 1) with the subscription and 2) with the latest virus and other computer threats.
So, no, your old, unused keys of Norton aren't really worth anything as they are not going to be that update on the latest threats to people's devices. The times to sell the codes is the year you purchased the codes. Or only buy enough that you need or go in on them with a friend who also needs them.
