This post made me think, actually, recently I've been thinking, Its sooo easy if you wanted too, to make loads of money window cleaning. I wouldn't put that effort in cos of religion and all that. But you could.
I have to turn customers down now. You just grow without trying. Over a few years you look and think, oh man I've got loads of customers withot trying, in a year I'll have loads more.... Take someone on or cut back!