Thales Teixeira, associate professor at Harvard Business School, believes many startups fail precisely because they try to emulate successful disruptive businesses. He says by focusing too early on technology and scale, entrepreneurs lose out on the learning that comes from serving initial customers with an imperfect product. He shares how Airbnb, Uber, Etsy, and Netflix approached their first 1,000 customers very differently, helping to explain why they have millions of customers today. Teixeira is the author of the book "Unlocking the Customer Value Chain: How Decoupling Drives Consumer Disruption."