Just judo here. However, if we were talking strategically, I think there's some benefit (depending on your local market, of course) of offering related martial arts. For example, if you have a long term student, who happens to be a brown belt in BJJ attending your judo classes...why not have him teach BJJ one or two nights (in exchange for free judo classes) a week and see what that brings in? That would be my thinking if I were a school owner.
It's actually quite a puzzle. On one hand, profitability related with multiple offerings. On the other hand, strong brand identity in the community ("Hey, when I think of excellent Judo, I think of X").