  An expert seller chooses an experiment to influence a client's purchasing
decision, but may manipulate the experiment result for personal gain. When
credibility surpasses a critical threshold, the expert chooses a
fully-revealing experiment and, if possible, manipulates the unfavorable
result. In this case, a higher credibility strictly benefits the expert,
whereas the client never benefits from the expert's services. We also discuss
policies regarding monitoring expert's disclosure and price regulation. When
prices are imposed exogenously, monitoring disclosure does not affect the
client's highest equilibrium value. A lower price may harm the client when it
discourages the expert from disclosing information.
