Free Gifts (or, My Brain Is Too Fried to Think of a Better Title)

Is there such a thing as a free gift? I think it depends on how you define "free". If you mean free of any obligation whatsoever, then I say no. After receiving a gift, one is obligated to give something to the giver, whether it's an object, your friendship/loyalty, your affection, or at the very least, a show of appreciation.
It may also depend on how you define a gift. In a close friendship, two people regularly give eachother "gifts", so often that they can't really keep track of reciprocation. For example, imagine that you give your friend a small gift, like a book you think she'd like. A month or two goes by and she hasn't given you a physical gift. But she did buy you lunch a couple weeks back, and brought you coffee for a late-night cram session. In such a relationship, the focus is on showing that you care for the other person, not on competition or obligation.