Not every tech product or service should be a business, an even smaller set should be venture-backed startups, and plenty of potential $100 million companies fail because they raised capital as if they would become billion dollar unicorns. The problem is that it’s hard to tell how big an idea can become at the outset. It wasn’t immediately obvious that an operating system for Altair microcomputers, a search algorithm for academic papers, or a social network for Harvard students would become three of the defining tech companies of our times! So how should a startup that is unsure about its ultimate scale proceed? Carefully, says David Frankel.