Some context:
I'm a 1-man operation, no sign out front (yet), within sight of the local Napa (with whom I have a good enough reputation that they recommend me) on a high-traffic street in a town of about 11,000 people. I have no published hours, but I'm here most of the time and usually Saturdays, too (whenever there's work to be done). Most of my customers are part of the community centered around my church of ~300 people. I've no problem working for anyone that contacts me, but the church community is loyal enough that they usually keep me at about 70% capacity so I'm not in a huge hurry to get tons of walk-in business which will also bring more of the impoverished segment in, as well - I fix cars right, warranty my work, shop rate is $60/hr., and if you want a better deal than what I already give you can get it somewhere else. The two people I've had stand me up on payment so far were not people from church - go figure. I'm usually already acquainted with someone before they contact me about repair work, but most of the time it comes through references from other people, not self-marketing. And when a repeat customer texts me about an oil change that afternoon or the next day, 90% of the time I'm waiting on them. The bigger the job, the more lead time I need. CEL checks are free most of the time and OC's start at $30.
I'm certainly plotting a trajectory to grow the business, eventually hire help, move into a bigger building, and advertise as most shops do. A far different, but more conventional, business growth plan would not be as fulfilling to me and less friendly to the customer - I don't do this to get rich (I DO care about making money), I do it to provide comfortably for my family, find fulfillment, and help the people in my community by being more honest and thorough than 90% of the shops in the area. And I do it by appointment.
Would you rather pay the dealership rate for OC's and diagnostic checks, list price for parts, and as a recent customer did, spend $2,000 to have them tell you you need a PCM for $1,000?