In the mean time this is what pops into my mind:
* What about the people who don't care to go to anyone else other then their regular barber?
* Do you think they're will be push back since you are creating more work for the barber who has a pretty simple process. (cut hair, small talk, sweep hair)
* Also, a lot of places do cash only and you are going to create a paper trail of money, where some might not want it. (Shocker: Some people don't report all of their earnings.)
Is there a reason why you are not including the other 50% of the population (women). I would think salons would be more interested in this service than barbershops.
Since my girlfriend works in this industry I too have tried to think of ways to solve some of these problems for her. My idea was to create a simple scheduling/ calendar web app that is mobile friendly. The Barber/Hair Dresser can use their smartphone to scheduled appointments. If the barber makes their schedule public, on the salon/barber shop website clients can go and see what particular days and times are open. The client can then submit a request for certain day/time and the barber is notified(maybe email, or sms - twilio). The barber/ hair dresser can then approve the date and the client is notified.