Myrkul, got your point, but I don't agree with you and I am somewhat puzzled that you can have such a view on the personal part of human interaction. The business call example is just an example - I'm talking about being there in conversations:
Yes, that's all well and good, But I think the difference here is that I do not, and never have, "zone out" when in a conversation. I am always engaged in the conversation, whether that is a tech support call or a transaction with a check-out clerk at wal-mart. I am always "there." I've worked in both outbound sales and inbound support environments, and I always did better in the support role for just that reason.
All I am saying is that a sincere 'Thank you, John, you've done a great job helping me today," is just as effective at breaking a call-center rep or a secretary or whomever out of their work-trance. And it does so in such a way that will not get them reprimanded for letting a call go too long.
In other situations, perhaps extending the conversation is not so detrimental, but it can still get you or them in (at least minor social) trouble. Take the supermarket check-out clerk, for example. Sit there and talk with them for a few minutes, and you'll sart getting dirty looks from the people behind you in line. Take a little longer, and maybe the manager comes over to see what the hold-up is. Keep pressing it, and soon you're no longer allowed in that store again, and the clerk thinks you're a creep.
But a simple smile and thank you could have avoided all this. Make eye contact, smile, and thank them, wishing them a good day, and they feel valued, you have reassured yourself that you're not an asshole, and best of all, you haven't wasted anyone's time.
You don't have to go out of your way to convince yourself you don't treat people like machines. Just treat them like people, and the rest will follow naturally.