1) Context is everything and depends on which of the theories will work. In a Consulting environment, I’ve seen team members bees particularly motivated by Pink’s model. In other contexts, particularly when there is an initial resistance to change Expectant theory and ensuring “what’s in it for me’ is clearly communicated can be a key indicator of success.
2) Like another respondent, I’ve seen far too many behaviourist approaches of throwing money at the ‘problem’.