Workers in the hospitality industry need to know the proper way to greet their customers. If they are not formal enough for a given situation, they will make the guests feel uncomfortable. The guests may not feel that they are being treated respectfully or that the service is up to proper standards. On the other hand, excessive formality (for a given situation) can also leave guests uncomfortable. It can make them feel that they are in a situation where the staff is not friendly and welcoming.
The staff of any business in the hospitality industry must understand how to act with the proper level of politeness for various types of guests in various different situations. By doing so, they will be able to give the guests the sort of experience that they expect and with which they will be comfortable.