It's tricky tipping staff because money is a topic avoided in France, so it would be awkward handing them anything directly--though I'm sure it's what most people need more than anything else. However, letting them know you how much you appreciated their hospitality and that you will put a glowing review on websites, and name the people and how they helped you would be appreciated. Also, a note to the owners, letting them know how the staff helped would be appreciated.
I once sat down with the owner of an inn in the Tyrol to get the family history of the place, which I then incorporated into my review on TA. The owner was delighted to tell the history.
I always leave something for housekeeping, though they are paid better than in the States; these people are at the bottom of the ladder. If it was the same person daily, I'd leave 5 euros for the three days, or you could have left one or two euros daily.