The Desktop Tower Defense game story

Desktop Tower of Money: 3 tips to profit from casual games – GigaOM

Make a Flash mini-game, let people play it for free, and watch the ad revenue pour in when the site gets 20 million pageviews a month. That’s the option Paul Preece took with his phenomenally popular Desktop Tower Defense, and though he has no professional experience with game development, the Visual Basic programmer is now making, by his estimate, high four figures monthly for his ferociously viral little game.