It's easy to get caught up in the hype around internet business models, the sharing economy, and the loose connections between everything from Wikipedia to couch surfing to the maker movement to open source software. It might seem like open thinking is sweeping the globe and our triumph over outdated economic models is imminent. But if you scratch the surface a bit, I think you find some stark differences between open source and what most breathless commentators describe as 'the sharing economy.' One is about giving away something of value in order to create something new and more valuable, the other is about deriving conventional value from things that already exist. With this difference in mind, we’ll look for examples of truly open models, examine their parallels, and see what they tell us about the economics of abundance vs. scarcity, and what being open really means.