This one is kinda different but it works.

When I was involved with Student Government I'd always try a get the people that lost the election to be a part of the staff. This way they had to put up or shut up. Either they were in it for the Student Body or for their resume.

It 'forced' them in essence to do better cuz if they failed it would affirm the student's initial decision that they weren't the best person for the job.

I haven't had a chance to try this out in a workplace.