The Fed would do this, Bernanke explains, to influence the market for foreign exchange, i.e.

FORBES: Peeking Into Ben Bernanke's Bag Of Unconventional Monetary Weapons

Years ago I worked in Germany as part of my firm's foreign exchange program.

FORBES: Magazine Article

Back to that Economics 101 course: I learned that there is a connection between the supply and demand for dollars in the foreign exchange market and the demand and supply respectively for foreign goods and services.

FORBES: QE2, Trade and Black Box Economics