Automated reminder texts — anyone actually seen a big drop in no-shows?

does anyone use automated reminder texts? my friend who runs a beauty studio swears by them. she reckons no-shows dropped by something like 60% just from sending a message the day before. feels obvious in hindsight but i just never got round to setting anything up. is 60% realistic or is she just lucky? and does it matter whether it's a text vs an email in terms of open rates?