Compare with a major utility or bank. You may even be faced with an automated answer service to make sure you get through to the right department. By the time you speak to a competent person, in the right department etc etc, you will be delighted at the speed and efficiency that they have got you through to the right person. So you've answered the phone. In this case, it's the first thing you say on the phone.
Directory enquiries is a case in point.
There is no eye contact, no lip-reading, no gesticulation, no nothing. All you are left with is a disembodied voice at the end of your ear. It takes some adjusting. So the best thing to do is start your salutation with some rubbish. Giving your name is another Good Thing.