[Fnoord]

Well, they'll always contain a % of THC and CBD. Together with their taste and freshness, people become a regular of a certain strain from a certain shop because then these factors are the most static.

If you check strains on e.g. Leafly you can see that most are hybrids, and you can also see their ancestry (how they came about). Although in the shop I worked, hybrids weren't sorted as such; all strains were sorted on effect. Clerks were smokers themselves, so they knew what they were selling, because they knew whether they'd get stoned or high. New strains were enthusiastically tested.