Honestly, how are they getting people to fall for this?

it's not so much that they need to pay to do the exercise, but a sort of indirect psychology thing, where they're really paying to stay motivated to go and do it.

for example, when i pay to be a member of a martial arts dojo, i am there for every damn class. but when i just play around with some other people in an open club type setting for free, it's a lot easier to get lazy and not go.