There are stored-value cards, which allow customers to load money onto a microchip-bearing piece of plastic.

ECONOMIST: Next, cyberlaundering?

The company points out that customers can't bank with the card or use it outside the U.S. But other stored-value cards, often branded by Visa or MasterCard, can be accessed for cash via atms worldwide and reloaded with cash online or at checkout counters without a bank account or face-to-face identity verification.

FORBES: Cash Is King

These stored value cards give kids without credit cards a way to buy the in-game virtual currencies with real money.

FORBES: PlaySpan Scores $18M In Series C Funding, Nearly 50M Unique Users