DH - tips from houseguests?

I was just reading another post which mentioned tips given to a helper by houseguests. What are people's views on this? I said no, when I was asked before by one of my guests, but actually I have no idea if this is a normal practice or not.

You may have read my posting. To put it in perspective my sister was here for 15 days with her hubby and three small children (5, 3, 2) over Christmas and New Year. She babysat them (plus my 3) did all the ironing washing, cooking and cleaning for 10 people.... so she earned not only a bonus from me but they asked what they could buy her as they had had the best holiday ever (no work basically) so I suggested cash and nice card as she doesn't "need" anything as much as she needs cash. If my houseguests didn't suggest it then I wouldn't bring it up or suggest it but may give a bonus to her myself, after all I invited them and I would have looked after them myself if I had been in Aus or England. Still, if it is only for a night or two, then I don't think there is a need. In my case she worked extremely hard and extremely graciously and made a family holiday uforgettable for all the right reasons. Only downside - they had such a good time they want to come twice a year!!

Thanks a lot! That seems sensible to me. By the way, you seem to have a fantastic helper!