I think that giving can be an act of self intrest if somehing is wanted in return without a previous agreement. For instance, your little sister gives you a candy bar expecting a cookie in return, but she never asked for one.
On the other hand, there is selfless giving, and this can be simply letting someone ahead of you in line, or, as I plan to do should I die anytime soon, to donate your organs, because what benifit are they to you once your dead? And they can be a tremendous help to someone else... So in the sense of the question, you could say that its not "giving" unless it is selfless, otherwise its trading