Originally Posted by MSPeconomist

Part of it is simply training staff at all levels to pay attention. For example, if a housekeeper notices that you prefer one type of the coffee capsules being offered, they bring you more of the same type. Similarly for the thermostat setting: don't change it and make a note for the guest's next stay. Notes are made about all kinds of preferences and, if the hotel belongs to a chain, the hotel makes a point of consulting notes from stays at other chain members, including special requests that might have been forgotten by the guest, such as extra towels/pillows in the room, feather free or nonsmoking rooms, etc. It helps too that these hotels tend to attract better staff and usually there's little turnover. One suspects that most such places treat their staff extremely well in local terms, and these jobs can be considered by locals to be extremely prestigious even for positions that normally are minimum wage work in other establishments.

One one of my first repeat visits to a renowned European palace hotel, I was impressed when, upon offering my passport at check in, the response was that the hotel would never ask for any information that I had already given to them.

More recently, when I stayed for the first time in a luxury hotel that belongs to a chain in which I have top tier status, when I was escorted to my room, the person mentioned that the thermostat had been pre-set to my preferred temperature and my favorite wine had been provided as a welcome gift, but if I would prefer some other wine....