  A patient firm interacts with a sequence of consumers. The firm is either an
honest type who supplies high quality and never erases its records, or an
opportunistic type who chooses what quality to supply and may erase its records
at a low cost. We show that in every equilibrium, the firm has an incentive to
build a reputation for supplying high quality until its continuation value
exceeds its commitment payoff, but its ex ante payoff must be close to its
minmax value when it has a sufficiently long lifespan. Therefore, even a small
fraction of opportunistic types can wipe out the firm's returns from building
reputations. Even if the honest type can commit to reveal information about its
history according to any disclosure policy, the opportunistic type's payoff
cannot exceed its equilibrium payoff when the consumers receive no information.
