Money is a commonly accepted medium of exchange. Economic exchanges without the arbitration of money are called barter exchanges. Barter exchanges become extremely difficult in large economies because of the high costs people would have to incur looking for suitable persons to exchange their surpluses with. Money also acts as a convenient unit of account. The value of all goods and services can be expressed in monetary units.
ThriftBooks sells millions of used books at the lowest everyday prices. We personally assess every book's quality and offer rare, out-of-print treasures. We deliver the joy of reading in recyclable packaging with free standard shipping on US orders over $20. ThriftBooks.com. Read more. Spend less.