Virtual coin and card

Most explicit or implicit virtual coins are simple specialized credit cards that close an S&L loop.
Consider the standard household shopping credit cards. If you ship like the typical american shopper, then you get better short term loans deals and better short term deposit deals.

It makes a lot of sense, it keeps shopping trips productive for the shop keeper and the consumer. In the sandbox model, as we have seen, implementation is easy, the smart card can promise to shop like your typical amber. When you exceed the bounds, the smart card will pay the excess in another coin, or take from another account.

So, where is the boundary between the app, smart contract and pure cash? It is the software behind the smart contract.  For the typical shopper, the smart card can estimate good prices, operationally, because you and the app builder have agreed to valuable categories of consumption.  That means pure cash can trade for goodies, it has a learned set inserted by the app builder.  The app builder takes its cut, it has constructed an external model of store and deliver, and built its contract about that.  The app builds has abstracted linear cost measures that, mapped tore/green, allow the pure cash device to trade goods, against each other.  Smart contracts, where all the innovations and gains are made.

Fixed point solution happens because all the typical consumers adapt to one container size, and automated delivery is very simple. Users of the coin would be incentivized to place secure receptacles a curbside.