Trade economy is one the foremost and oldest form of exchanging goods among people. When I was a young boy, long before sports and girls had started to occupy our free time, I was in the habit of collecting and exchanging cards. There were cards with sport or movie stars captured during their “heroic” moments. We collect the cards from gum packages and we trade them in order to manage to have a full collection. I remember, that with a full collection you would get a wonderful album to keep the cards you have collected in and various other small gifts. The price was not such great, but the process of locating, trade them and negotiate for the cards we haven’t in our “repository” was exhilarating!