Relationship Bank

I was just reminded of this, and since it was so helpful I thought I'd post it so I didn't lose track of it again.

Kev once told me about a concept he'd run across called the "Relationship Bank" (or Emotions Bank, whatever). The counselor likened interpersonal relationships to banks:
Every positive interaction / emotion with someone meant they made a "deposit" of Good Feelings in their "Relationship Account" with you.
Every negative interaction / emotion with someone meant they made a "withdrawal" from their "Relationship Account".
Obviously, we need to keep our accounts in the POSITIVE with other people we want to get along with.

Granted, it's rather a simplistic -- and slightly mercenary way -- to look at relationships on the surface, but I think it's actually a solid and valid way to evaluate your relationships with people.
Have I been "depositing" or "withdrawing" lately from my friends? If I'm "withdrawing", have I "deposited" enough prior to this that I have a healthy balance to draw on? If not, maybe we're not as close as I thought, and I should be more careful about my "withdrawals" from them.
And that other person over there, who's doing nothing but "withdrawals" from me - do I know them well enough to allow this? Do they have enough "on balance" to do that, or are they taking advantage of my good nature? (Okay, stop laughing now, it's a hypothetical question, not one I'm asking myself. I said STOP LAUGHING.)

It's interesting how many "friends" really turn out to be nothing of the sort when evaluated this way - especially those made over the Internet. How much do you know about these people, anyway - these faceless, pseudonymous people who type at the world in general on their computer?