Miss Snark is your agent. She is not your friend because:
1. you have enough friends. you only get one agent (at a time).
2. You can not invite her to your wedding/kids' parties/holiday festivities and she won't be insulted.
3. You can't call her on Sunday to discuss your marital woes.
4. You can't call her on any day of the week to discuss your mother.
5. Miss Snark is going to hear people say disparaging things about you and not send her seconds with a summons to the field of honor.
You'll notice none of these things are "miss snark is not your friend because she doesn't like you".
I think it's insane that I actually though I'd write "but I do like my clients, I do". Of COURSE I do, and your agent will like you, or does like you. But we are your AGENTS and our role in your life is different than that of a friend.
I can't understand why people get in a tizzy about this. Do you tizz if your dentist doesn't ask where you got your shoes? Do you tizz if your college professor posts office hours and asks you not call her at home on Sunday absent an emergency? Of course you don't.
I fully expect long standing, profitable, warm and cordial relationships with each and every one of my clients. I don't expect them to invite me to their birthday parties and I'm not offended if they don't. I am however, hostile as hell, if they fail to acknowledge me in the books I've sold for them.