Many breakthrough technologies were hatched by hobbyists in garages and dorm rooms. Prominent examples include the PC, the web, blogs, and most open source software.

The fact that flip-flop wearing hobbyists spawn large industries is commonly viewed as an amusing eccentricity of the technology industry. But there is a reason why hobbies are so important.

Business people vote with their dollars, and are mostly trying to create near-term financial returns. Engineers vote with their time, and are mostly trying to invent interesting new things. Hobbies are what the smartest people spend their time on when they aren’t constrained by near-term financial goals.

Today, the tech hobbies with momentum include: math-based currencies like Bitcoin, new software development tools like NoSQL databases, the internet of things, 3D printing, touch-free human/computer interfaces, and “artisanal” hardware like the kind you find on Kickstarter.

It’s a good bet these present-day hobbies will seed future industries. What the smartest people do on the weekends is what everyone else will do during the week in ten years.