People exchange goods and services for other goods and services of equal value in return. It's a win-win situation for both parties. Just in the past month alone, I've bartered with my pewter supplier and another vendor too.
My pewter guy needed some supplies to safeguard his products and I have a wholesale account with a company that sells them. I got pewter pendants and cloak clasps. He received an equal value of what he needs to display and protect his products.
The other vendor fell in love with my goddess pendants and wanted one for herself. I was attracted to a zebra jasper pendant that she had on display at her booth. We both went home happy. *smile*
Here is the pendant that I received in the exchange.