I am only starting my second season, but I have learned very quickly all of the issues that other operators mention above. I was growing and doing pretty well through September...then all of my customers started "laying me off" because the grass was not growing quite as much so they didn't want me to come by...even though it should have been mowed.
This season I have implemented a service agreement approach and am getting a little pushback. I have allowed my previous customers to remain on a bi-weekly schedule, but I'm going with a weekly schedule for any new customers. I'm also adding fert and squirt, aeration, and shrubs/bushes as additional services this year that I did not do last year. I'm committed to keeping this service agreement approach because those are the kinds of customers that I want. I believe that is the way to grow a solid business and will eventually get me out of the seat of the mower and into the seat of the office/truck.
I do not want to be known as Joe-Bob the grass cutting guy. I want to be known as a Lawn Service with professional appearance, professional work, and professional clients.