The Economist recounts some of the unexpected tipping that is suggested for when people travel to the U.S.:
The American Hotel & Lodging Association, a trade body, publishes a “Gratuity Guide”, with suggested rates that can make one wince. Examples include up to $2 per person for the driver of the shuttle bus from the airport to the hotel; as much as $5 per bag for porters; door staff, meanwhile, should expect up to $2 for the onerous task of flexing their fingers at one of the taxis queued up right outside; and housekeeping should be left up to $5 a night. Top of the heap is the concierge. His suggested rate is $5 for booking a guest a table in a restaurant and $10 if he has something more difficult to do, like find a tricky theatre ticket.
As the article mentions, this all sounds crazy, but it’s a systemic problem: most of these employers don’t pay their employees minimum wage with the expectation that tips will make up the difference. As a restaurant server in college: good luck getting the restaurants to pick up more of the server’s salaries just to lower the expected tip amount for patrons.