When credit cards were first introduced, they were a pretty simple proposition: use your card for purchases, and be charged a single rate of interest on your unpaid balance.
Then came the rise of the ATM (cash machine), and credit card issuers realised they could lend money by allowing their cards to be used to withdraw cash on account, and could earn more this way by hiding away a higher interest rate for cash withdrawals in the credit agreement small print.
Next came the balance transfer offer, with either long term low rates or an introductory 0% deal, closely followed by introductory deals on purchases too. Not to forget the different interest rate often charged for overseas use.
All these different rates for different kinds of card use can easily become confusing, and survey after survey showed that many credit card users were unaware of how much their card use was actually costing them.
In many respects, this suited the card companies down to the ground as they could advertise eye-catching rates for purchases and balance transfers while quietly imposing more lucrative charges on other kinds of card use.
Amidst all the confusion though,...