One criteria I've seen used to price domains as "premium" is shorter names and popular dictionary words. Not sure if this is consistent across registrars, but

One criteria I've seen used to price domains as "premium" is shorter names and popular dictionary words. Not sure if this is consistent across registrars, but I would think "premium-ness" is established at the registry level. It's unclear to me if premium-ness is a function of time, and/or if there's an objective formulaic criteria here.