OK, so possibly that is a little far fetched. But, I think you get the concept. The art of bartering has been about for centuries. In fact, we still barter every day. The only difference is the medium of exchange. We use paper money, coin or "plastic."
Kids trade baseball cards, radio stations trade ads with television stations and folk in service industries exchange their services often. A pipe fitter inevitably his home painted and a painter inevitably a new bathroom installation.
What you probably don't know, is that bartering is being done every day on the Internet. Possibly you are a terrific graphic artist, but simply don't seem to be able to string a few words together to write a solo ad.
Somewhere online, there is a troubled employee who inevitably graphic wor