Mardi Gras beads are a good example -- nobody does anything for Mardi Gras beads that they aren't sort-of looking for an excuse to do anyway. Offering them a tr

Mardi Gras beads are a good example -- nobody does anything for Mardi Gras beads that they aren't sort-of looking for an excuse to do anyway. Offering them a trivial reward just gives them an excuse.