I worked at a coffee shop, and we just served the customer. Guys care a lot more about just getting their coffee and leaving than women do. Women are much more social and appreciative of deliberate, professional, and courteous service - especially when men are serving them. So, we focused on giving them this. They really care how you treat them at the register. Men just want their drinks fast, so we focused on giving them this. Women didn't seem to care as much about this. So, we tried hard to give both groups what they wanted most. I could probably do the following study and get results something like this to show the impatience, rudeness, and sexism against male customers in coffee shops:

"The results show that the men received shorter initial greetings (as measured both in number of words and in the duration of the greeting), less eye contact, less total exchange of words, and were rushed from the cash register in approximately half the time given to the women."

There is one more possible factor here. In serving the customer, we had the tendency to talk more to the open and chatty people. The fact that more of these happened to be women doesn't mean that we were discriminating against men.

Also in serving the customer, we had the tendency to rush drinks to impatient looking people who seemed to be in a rush. The fact that more of these happened to be men doesn't mean that we were discriminating against women.