As a product YouTube was a runaway success -- growing to 100 million daily views during its first 18 months - and of course uploading & streaming video is much more intensive than just serving a webpage. Hypergrowth sites have one job to do: stay running under incredible load. Steve Chen still shivers a bit when you ask him about the rate at which new servers were being racked those days. YouTube managed not just to stay operational but continued to release new features at an amazing pace.
The quality and rapid growth of the team was the most significant factor in why YouTube succeeded. Almost all of the early technical/product/UX hires were previous colleagues or referrals. What a competitive advantage! Imagine being able to basically skip sourcing, interviewing, training, team building and fast forward to just working at a productive clip. As YouTube expanded they were able to bring on new talent very quickly. Attribute this not just to the fact it was a 'hot startup' but to the close relationships everyone had with one another. They just enjoyed working together at a personal level. And anyone that has spent time with Chad & Steve know there's a warmth, charm and charisma present.
The YouTube story is not just about luck or timing but execution, and that's part of the tale often ignored in their success. When we talk about founders we often like to hone in on their raw intellect but the ability to pull a team together is equally valuable and in the end, probably has more to do with success than any of their other talents. That's why it doesn't surprise me to see YouTubers sticking together at new startups such as Endorse and TheIceBreak. One gutcheck for entrepreneurs and leaders: would your former teams/colleagues work with you again? If the answer is "no," then you are going to have a very hard time succeeding.