1.7.1 update: per user request added dog groomer and cat groomer1.7 update: removed ads and Internet requirement.Offering someone a monetary tip for providing a service is quite common in the United States. Tips can be optional at some services, while they are customary at others.Consult this concise, helpful list when you are travelling or trying a new service and are wondering if and how much you should tip.Note: Tips are estimated only for the United States, and should not be used as a basis for tipping non-United States service providers.