9. The method as in claim 8 , wherein identifying the desired amount of reward includes: identifying a first desired amount of reward generated for each selection of a first portion of indexed content; and identifying a second desired amount of reward generated for each selection of a second portion of indexed content, the first desired amount of reward greater than the second amount of reward.
8. The method as in claim 1 , wherein ranking the multiple portions of indexed content includes: identifying a desired amount of reward generated for selection of at least one particular portion of indexed content; and modifying a rank position of the particular portion of indexed content based on the desired amount of reward.