interest rates, gift cards, or cash. The points can also be exchanged, sometimes, between cooperating programs of different banks, making them more and more currency-like. These programs represent such a large value that they are not-completely-jokingly considered a set of currencies. These combined "currencies" have accumulated to the point that they hold more value worldwide than U.S. (paper) dollars, and are the subject of company liquidation disputes and divorce settlements (Economist, 2005). They are criticized for being highly inflationary, and subject to the whims of the card issuers (raising the prices after the points are earned). Many cardholders get a new card or use a card for the points, but later forget or decline to use the points, anyway. While opening new avenues for marketing and competition, rewards programs are criticized in terms of being able to compare interest rates by making it impossible for consumers to compare one competitive interest rate offer to another through any standard means such as under the U.S. Truth in Lending Act, because of the extra value offered by the bonus program, along with other terms, costs, and benefits created by other marketing gimmicks such as the ones cited in this article. References Credit card terminology Interest rates Mathematical finance