Trading flea market goods and services

Here we have a labor and goods trade, a sort of m distributed flea market for services and used goods. No need for a trading pit, cards can handle this directly. 

Bloomberg:

When her car broke down, Halima Cassells didn’t have $400 to fix it.
But she had logged hours in her Detroit neighborhood time bank by babysitting, and that time yielded a repair. When she was pregnant in 2012, she couldn’t afford baby clothes, a stroller, or a car seat. But she could throw a potluck barbecue, and her friends could afford to bring their old baby supplies. “When people come together to share, it’s not transactional,” says Cassells. “Everyone assumes an amount of responsibility with everybody. It’s a different way of knowing your needs are being met.” Detroiters like Cassells, after years of privation, have turned to what experts call a gift economy to survive. Theirs is an alternative economy based on time banking, skill-sharing, and giveaways—home-grown vegetables, a roof repair, spare keys to a shared car—in which neighbors give as they can and take as they need.
 It’s a currency of community that has helped Detroit’s poor survive without ready cash. And those who rely on it say it has helped strengthen communities throughout America’s poorest big city, where nearly 40 percent of people live in poverty and about 11 percent officially are out of work.

The smart can can be set up for this with the associated app, it does card to card exchange directly.  But the logic in the card needs a menu from the app which runs on one's external compute device, the the only collective action is membership.   

The complicated part is morse coding your smart card onto the local exchange coin when you flea trader.  My simple card model says you have a short tap code, ta-dum, and it gets the proper mini-app running on the card. The basic smart card model has no button, but it taps mechanically, like a mouse.

Distributed fairness here works as follows.  Among the two trading, naked, the one who scaned the web site for updated prices has  to give up the information to the other, then the card can red and green it to conclusion. The common set of traders know enough to look at and report pricing now and then. The cards insure information fairness.

But once in the flea market coin function,  transaction between  seller and buyer does he trick.  Service or goods units are loosely priced, the tree is sparse and slow, each card can assume the distribution table leading to stable card to card plays.  We want the pit when congestion is the issue.

The card itself never gets programmed, it gets a parameter set, including a protocol, together called the coin function.  It is as if the web site app was allowed to implement a spreadsheet function, without macros, in your card.