When went out of town for an internship a few years ago, I was a very frequent patron of a couple chain shops near the office and one independent shop downtown. I could work on personal projects and enjoy a few drinks without being disturbed. I was in often enough over a six month stretch to recognize most of the staff. Even so, I don't remember seeing more than a few repeat patrons, and even they were only around two or three times. I may have just been around at the wrong time of day, but I covered pretty much every time slot on evenings and weekends.