I think that very different things are happening all over the world, so it's hard to say for sure what your course of action should be.
Where I am, Zumba has a big following - it can pack the room with anywhere from 30-60 people. I get 35 Jammers on a good day, around 25 on a normal day (the club I teach Jam at has a very small studio, so 35 is about capacity; I have no idea how they squish 60 Zumba-ers in there).
We have Jam instructors and we have Zumba instructors, and nobody teaches both programs. The Jam instructors tend to be the people with dance backgrounds whereas Zumba instructors are "regular" fitness instructors who just like to move. That's not how it is everywhere; it's just the way it shook itself out in my region. For this reason, there is a pretty solid division between what Jam *is* and what Zumba *is*, in the minds of our participants: they consider Zumba to be the nurturing approach to dance-based fitness that anyone can do, whereas Jam attracts people looking to push the limits of their dance skill and coordination.
This sharp division we currently have between the two works. Both classes thrive. Since Zumba has been introduced, I have seen more people in my Jam classes. Because Jam was around a lot longer than Zumba, and has a tight-knit community of Jam freaks, newbies always looked at it as "Maybe a class to work up to... someday." They were too shy to try to break into that tight-knit group of Jam addicts. But Zumba made dance classes accessible for a lot more people, and once people got a few Zumbas under their belts, they were more confident to try Jam.
I have been encouraging people to try Zumba (even though I don't teach it and don't particularly enjoy it), because I know that, eventually, those Zumba-ers might turn up in my Jam class. And heck - even if they don't, at least they're getting some fun cardio in. I don't love Zumba, but it's sure a lot more fun than an elliptical machine!
I definitely didn't lose any Jammers to Zumba. The two programs coexist well in the club where I teach Jam. I'm sorry that it isn't working for you. I am sure that if the situation were different where I teach, I'd be just as frustrated as you are. But maybe the same thing will happen to you - maybe all those Zumba freaks will turn out to be BodyJam freaks someday. I wonder if you and a Zumba instructor could get together to put on a Zumba/Jam combo class to help showcase BodyJam to Zumba-ers who might be too scared to try it?
(Oof. Now that I think of it, suggesting a Zumba/Jam combo is probably a little blasphemous! *grin*)
Personally, I advocate Zumba in the clubs because it has been helping my Jam classes.
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