Suppose you are selling wine in a store, pouring in a restaurant, or pouring in the winery tasting room. In that case, your goal is to make each wine interesting, if not their favorite, and to make the overall experience a memorable event.
If you are in the restaurant business where wine is available by the glass and bottle, guests who like the wine will buy more wine (owner/manager likes that), tip more (you like that), return more often, and possibly ask for your presence on that return visit (job security).