Gym promotion: Annual membership card 3888, check-in 200 times within a year, full refund.

I calculated it—going 4 times a week is enough, which means free training, a huge profit.
Decided to sign up immediately.
The sales guy smiled and saw me out, I couldn’t help but turn back and ask, “Aren’t you guys worried about losing money with this promotion?”
He smiled and said, “Bro, do you know how many people received the cashback last year from this promotion?”
“How many?”