I dont knock, i have 10,000 at a time go out, then about 2 months later another 10,000.
I always wait for the custie to contact me and ASK ME for a quote, rather than me asking them if they want a window cleaner. When they ask you, you are in control, hence you can demand a higher price!!
I come from a sales background, sold timeshare in spain, cars advertising. etc etc, so i still use some of my sales knowledge.
Door knocking is an excellent way of building a round, if you have the time, however, i found the way i do it, i can get better priced work!!
You jus have to be a bit patient, but believe me it works!!!