Imagine, for example, that you were thinking of starting Netflix back when it was founded in 1997. How would content providers, distribution channels, and competitors respond? How soon would technology develop to open a hidden door and let you distribute online instead of by mail? Or consider Dropbox in 2007. Dozens of cloud storage companies had been started before. What mistakes had they made? How would incumbents like Amazon and Google respond? How would new platforms like mobile affect you?

When you’re starting out, it’s impossible to completely map out the idea maze. But there are some places you can look for help: History. If your idea has been tried before (and almost all good ideas have), you should figure out what the previous attempts did right and wrong. A lot of this knowledge exists only in the brains of practitioners, which is one of many reasons why “stealth mode” is a bad idea. The benefits of learning about the maze generally far outweigh the risks of having your idea stolen. Analogy. You can also build the maze by analogy to similar businesses. If you are building a “peer economy” company it can be useful to look at what Airbnb did right. If you are building a marketplace you should understand eBay’s beginnings. Etc.