Mechanisms for controlling a commercial transaction are presented. An
article of manufacture has a time cell that is read by an electronic
apparatus. In response to a determination of a state of the time cell by
the electronic apparatus, usage of the article of manufacture in a
commercial transaction is enabled or denied based on the determined state
of the time cell. The expiration period of a time cell controls the time
period during which the commercial transaction is enabled or is denied to
be performed; an unexpired time cell may both enable or deny performance
of a commercial transaction, and an expired time cell may also both
enable or deny performance of a commercial transaction. The time cell may
be used to restrict the usage period of a coupon, a promotional offer, a
pre-paid service, or some other commercial transaction that involves an
article of manufacture.