Claer Barrett, the editor of Financial Times Money, says the Western world is headed toward a world without physical currency.

Barrett wanted to find out if the absence of physical currency does indeed cause a person to spend more, so she decided to conduct an experiment a few months ago.

Tencent's messaging system is used by an estimated two-thirds of Chinese Internet users and its QQ Coins have been accepted as payment by other companies as well as sold for legal tender.