I mentioned the Microsoft Live "gadget" competition derisively on Tuesday - where they're giving away a couple of xbox360s to the creators of the best gadgets, trying to entice some extremely cheap labour (split the marginal prize cost amongst the hundreds who'll probably take the challenge to win themselves a game system). Of course Microsoft is doing it to try to make their platform viable.
Firefox is getting into the game too: Develop the best extensions to go with Firefox 1.5, and you could win from a collection of prizes. It is sort of remarkable that the Mozilla Foundation prizes are so much richer than the Microsoft prizes - e.g. three absolutely top of the class gaming computer rigs as the grand prizes, versus I believe 4 xboxes, worth 1/5th the amount, from Microsoft (you would think Microsoft would at least pony up for a year of MSDN Universal or something for the winners). The Firefox competition also has impressive category winning bounties, including an iPod Nano and a $250 gift certificate.
Of course many enter these sorts of competitions not for the prizes, but rather for the prestige. For these people the prizes are almost an insult.
For the prospective competitors, in the Firefox case there is already a rich ecosystem of very impressive extensions, so you can go into that knowing that you're starting with a proven, rich platform. In Microsoft Live's case, there is a measly 8 existing gadgets, and they're a little weak. I'm always suspicious when organizations unleash that sort of platform on the world, because their lack of experience trying to use it in real world scenarios means that it is almost certain v1.0-borked - e.g. you can expect a complete rework and rewrite as people explore the edge cases, and discover all of the things that simply cannot be accomplished with the infrastructure they've developed. If you're a developer, you've probably been handed that sort of "framework" from a coworker, with grand promises of extraordinary extensibility, but in reality it's useless in the real world because they never actually used it for anything of consequence themselves.