Infrequent use doesn't help either, since the mechanisms can dry out.

WSJ: It Takes Brass to Play the Wagner Tuba | By Barbara Jepson | The Ring of the Nibelung

It's not just infrequent travelers who get burned, but sometimes road warriors who happen to switch programs and don't pay attention to the old program.

WSJ: Saving Frequent-Flier Miles From the Ax

While Russian spying in the U.S. is at an all-time high, U.S. officials say, and the U.S. hasn't pulled back on its efforts to spy on the Russians, public revelations of spy operations have been infrequent since the end of the Cold War.

WSJ: Russia Expels U.S. Diplomat