You'll never meet a happy ungrateful person, or an unhappy grateful person because gratitude and happiness go together. Sometimes happiness precedes gratitude but often gratitude precedes happiness. The latter is achieved by realising things could be worse but aren't and so feeling relieved, grateful and happy.
Selling is essentially transference of feeling.
Action often precedes the feeling.
I believe it's important that we use names of endearment that reflect a special feeling for the individual involved.