what stat controls speed you have to serve customers? Cause it seems like you get about 10 people and all want drinks at the same time and after about 2 seconds of waiting you get loss of popularity.
"Tip Windows Increase" increases the number of turns you have before a client becomes impatient. If you invest early on in "Number of Action" and then dump everything into "Tip Windows Increase," you can easily serve the maximum number of clients (17).