I know you have nothing but good intensions but it will come back and bite you on the bum trust me,i let a customer off a £100 bill for doing her shop as she said business was really bad,i said we`ll wipe the slate clean and start again from next week,a month later she said can i stop doing her windows i can`t afford it.What i`m saying is you might think your doing people a favour but they don`t always see it like that,i now do nothing for nothing even if it`s slipping a tile back in for someone they get charged even if it takes 30 seconds.