A prize, unlike a research grant, goes to someone who solves a problem, rather than just working on it.
That's just one of the virtues of multi-million dollar incentive prizes according to Peter Diamandis, the founder of the X PRIZE Foundation. His $10 million Ansari X PRIZE went to the SpaceShipOne team, when it made two manned flights into suborbital space in 2004.
We think these prizes can definitely be useful. Not so sure about his awkward new term "philanthropreneurs."