Paper money backed by government. People believe and trust in it.In the United States:1690 Colonial Notes The Massachusetts Bay Colony issued the first paper money in the colonies which would later form the United States.1781 Nation's First Bank Also to support the Revolutionary War, the continental Congress chartered the Bank of North America in Philadelphia as the nation's first "real" bank.
Barcodes are used for two purposes: generating communication for payment and loading prepaid gift cards into wallet.
The way consumers are shopping is changing. The adoption of smart phones are allowing consumers to control how, when, and where they shop. Consumers have more leverage.