There are positive aspects to using people's names in conversation with them; one of the most notable is that it makes it less likely that you'll forget what they're called! That said, the only time it has especially struck me was when I was working as a tech support monkey and one of my colleagues would tend to use the customer's name several times every call; I ascribed it initially to his Moroccan background, and some cultural conventions for of negotiating in the Medina, but later I learned that his background was sales, and given the other answers here, that's probably where it came from.