When Kellogg announced it would not renew its endorsement contract with Olympic medalist Michael Phelps after a photo of the athelete smoking pot surfaced, it may have cost the food company its sterling reputation, reports company reputation index Vanno.

Out of the 5,600 company reputations Vanno monitors, Kellogg ranked ninth before it booted Phelps. Now it's ranked 83. Not even an industry-wide peanut scare inflicted as much damage on the food company's reputation. A Vanno representative put together this chart:

We'd caution that while Vanno's data may be directional, it is certainly not exact. Vanno gleans it from real-time surveys on its Web site and then filters it through a Bayesian algorithm -- the same kind of algorithm that keeps spam out of your inbox and investigators use to spot insurance and credit card fraud.