But in this case the service being performed was not just vigorous, but extremely reminiscent of the restaurant work for which it's customary to leave a gratuity. ...

Does complimentary breakfast mean free?

A second meaning of complimentary is "free." If your hotel includes breakfast with the price of your room, they may call it a complimentary breakfast. It's easy to get complimentary confused with complementary, which sounds exactly the same but means "filling in or completing."

How much do you tip for breakfast buffet?

Sit-down restaurants and buffets

Tip somewhere between 15 to 20 percent for sit-down meal. Buffets can be less — about 10 percent.