Also this is data that any reasonable company could get in like half an hour of searching and asking.
There is data on how many meals are sold a day at the mensa, how many students are enrolled, how many students live on campus…
Unless the vending machine is in the last corner of the third floor of an half empty building, all this information can be puzzled together to get a good estimate of how many people are passing the machine on a day to day basis.