it is pretty easy to get them on a 2 or 4 weekly cycle really, you turn up give quote and say do you want it fortnightly or monthly hen, if they look at you like you like you have just raped or killed their daughter throw in or we can do 8 weekly,
Must admit most of the time I just say once a month all right
If the customer asks for something else then of course I will accommodate their wishes, but offer what you want to do not what you think they want, how do you actually know they prefer 6 weekly if you don't offer other alternatives, I have customers that must suffer from OCD as they would have me round weekly if I could fit it in