Discounted refills

Purchased 2 refillable bottles valued at $2 each such that every time I refill it at university dining services, I’ll receive a 10% beverage discount (courtesy catering manager). Saved $4 plus the future savings on the refillable beverages. But I wonder how well it’s advertised, as I don’t see a lot of students using it…aren’t they really the ones who need to save money?