As I stated before, for some auto-flower strains running a 12/12 is beneficial. On the other hand, running autos that aren't good for it on a 12/12, your yield and potency will suffer a bit in the end, but one of the best known benefits of running any auto-flower on a 12/12 cycle is *drum roll* a lower power bill. Not sure about you but I sure as hell don't want a jacked up power bill either draining my wallet or drawing attention to me. Or, people throw them in with they're flowering plants that are already on a 12/12 cycle. Not everyone has the $$ or space to have two tents or grow spaces. It's all about convenience my guy. Yes, the yield will suffer, but we grow the way we can grow given our circumstances.