Fair do's then.
Although the front only hits Mark gets shows he is not greedy as 99 percent of the customers will want there backs doing after the first clean too meaning the window cleaner cant lose as long as they do a good first clean, and with the first clean being just the front it means can spend that extra time getting it right. I think its clever how he goes for the front only without the greed to charge x2/x3 for whole houses like i used too as was only in it for the greed and quick pound note from guys who wouldnt canvass themselfs(not to say i ripped anyone off) as i always replaced dropouts or refunded money back. It is a verey clever way Mark does it which keeps him at top.
Its not hard to be listed on first page google as a window cleaning canvasser as there arnt many at all about.
If your hapf as good as Mark im guessing you will do well.