Why do retail workers say welcome in?

Why do retail workers greet customers with a warm "welcome"? Is it simply a polite gesture, or is there more to it? Do they believe that it sets a positive tone for the shopping experience, making customers feel valued and appreciated? Does it play a role in building customer loyalty and fostering repeat visits? And how does this greeting compare to other industries where customer service is also paramount? It's an interesting question that merits further exploration.