I've noticed a theme among the various motivational techniques, incentive programs, and reward structures I've been researching over the past hour or so, none of which seem any more or less likely to succeed than the next - it's about enough being enough. The way I see it almost anything should work, provided it's good enough to motivate, incentivize, or reward an employee. Is a monthly prize for the best performer going to increase productivity? It sure will, assuming the prize is good enough.
I'm reminded of an amusing few months from a past job when my boss created a bonus scheme to try and get us all to work longer hours - without going too deep into the details, let's just say the midnight oil remained in its unburnt state. If he had asked me for my opinion on the matter, I would have shown my boss what I'd calculated on the back of my pay stub - once I factored in the extra hours necessary to earn the bonus, I'd determined that it lowered my average hourly pay, so I'd decided that it was better to have a social life than to pursue the incentive; the bonus was a good idea, but it wasn't good enough.