Twelve years ago I took voluntary redundancy and started window cleaning fulltime. I bought a couple of small rounds to make ends meet but still found that I had a lot of time on my hands. As a consequence, every now and then, whilst engaged in conversation with neighbours of existing customers I would casually ask them if they would like their windows cleaned por-gratis.
In my experience, and i appresiate that this is somewhat isolated, not only did these individuals feel it incumbent apon them to insist on payment after my labour, but I still have them to this day.
As a direct result of these encounters, I have often considered swollowing the inevitable exploitation, and just give it a go in the roads of present customers.
Nick