yes I know mate some times it can work in your favour, sometimes not, I refuse the sometimes nots, some of these cleaning company's work it out on floor space

regardless of the amount of glass, so you can get an excellent price on a large shop with very little glass, but be asked to do a small shop with lots of glass, and some just do a price per store, and if you are lucky it works out ok, if not then not worth doing, but some company's are doing ok as they take the hit on the bigger stores and make there money on the smaller ones, all madness but that is it how it is