You walk into a store, you buy stuff, the screen shows how much you owe and makes inaudible sounds or radio waves. A simple device in your pocket wakes up and pays the bill. Or you snap a picture of a screen with price and address, and the app pays it. Or you swipe a card paying in local currency, which is automatically refilled from converted koin.
An open webpage or app could allow anyone to become a merchant. And it must be simple. Like Microsoft 95 to DOS, it must be totally backwards compatible with current financial systems.
Banks and others must be encouraged to begin taking this currency as well as dollars/euros/yen. There must be a very simple method of conversion, better than most competing currencies. Besides exchanges, there may be a blockchain conversion system usable by banks and institutions working in only one currency.
This what I see. This koin will be so steady the dollar will vary with equal or more roughness as itself. Somehow a rule set needs to be created allowing banks and merchants to accept koin with equal willingness as anything else.
The formula need not be some perfect conversion. There will be these two currencies (like koin and eruo) both being quite steady. Transactions can be divided into 8 or 12 categories and if one currency is accepted in place of another, an average comparison of product prices overtime is done for that transaction by its category. This may be easier or less expensive than converting at the current rate, like bitpay does presently.
One can say the cost/value in koin is this and in dollars it is this, or use the formula. On a large scale between banks and nations working with liquidity, exchange can be done as usual. But we have no desire for momentary money manipulation to disrupt daily workings of the average user.
It is possible that bitcoin can become all these things, but the problem is that its success means making richer the already rich. This has socio-economic implications. My strategy is to make investing in real companies the source of revenue for koin. But the value of a koin should stay pretty much level.
Automatic in the code may be an ability to constantly fill an account from which payments are made. There could be a limit like there is on a credit card, so that one stealing your everyday purchasing tools or passwords, cannot access your larger money supply. When working with a fortune or personal account, transactions can be carefully created offline using special tools.
But buying should be very simple. Very very user-friendly for both coders and laymen alike. Confirmations can basically say do you want to pay 50 koins (about 53 dollars) to SomeCompany at such and such address, and it can be standardized or have a protocol, so that one need never accidentally pay too much or little or to a wrong person/place.
Maybe a tool can be devised, which lets you pay someone online with a special key. If they fail to send the item, you can prevent/retract the payment by a special procedure. This procedure could be an POW blockade. The difficulty or cost can be high enough so as to discourage canceling of payment. Of course, they would have to accept this type of payment.
Maybe it could cost both, to set up or to try to surmount a blockade. Basically you get angry that they failed to deliver and you set up an costly blockade that is difficult to break and maybe they can try to break it. It's like going to court for a lawsuit, calling your credit card company, or an payment arms race... which may cost more than original payment. I'm not sure this is a good idea, but it came to mind as a way to allow safer online purchases. And one can always complain, of course.
In the end, there can be copy-and-paste methods, payment cards, or smart apps, but all should be easy to use and protect you from silly mishaps.
Basically typical payment processing should be expanded to accept alternative forms, and new types of processing can also be adopted. There is a semi-monopoly on processing but surely theres a place for blockchain in the future payment processing.
Checks can be done by sending a piece of paper with a transaction on it, representing an amount going from one account to another. Or a third party can verify a check in koin, where they hold limited access to your funds.