When we started, I only took on the work to suit the time I wanted to give the business.
So, domestic customers only took up a few mornings each week, during school hours. Commerical customer cleans were performed only on Tues & Thurs evenings and on Sat mornings.
I had, and have now, no intention to dominate the market. Having a nice, comfortable and manageable customer-base whom I have a great relationship with, as well as maintaining family-time, is more important to me than raking in a few extra £'s.
I have regularly turned down extra customers (in both sectors) as I want to retain MY time (for shopping, gym, etc!!). My business is a nice earner, but I guess I'm fortunate in that it isn't the main income for the household.
If I were on my own, it would be a completely different game, I'd imagine.