What Billion Dollar Companies look like at the Series A

My friend Joy shared this post with me earlier this week highlighting what billion dollar companies look like at their Series A. The study analyzed companies like Uber, Airbnb, Twitter, Snapchat,, Dropbox, Evernote, Tumblr, Waze, etc.... To summarize, these companies had 5 things in common:

1) Easy to dismiss ideas: How many people really ride in black cars?  Photo messages… that disappear?!?! How many people are interested in renting a couch in someone’s home? You get the idea...
2) Competitive markets: Conventional wisdom would say that successful start-ups go into wide open spaces with bold new ideas, but most of the companies in the study actually went into very competitive markets. (i.e. there were plenty of ways to communicate before Snapchat)
3) Reinventing existing customer behavior: Billion dollar companies generally reinvent existing behavior with a superior consumer experience, rather than bringing something totally new to the market.
4) Untested founders: Most founders of the billion dollar companies in the study were first time founders, not experienced entrepreneurs.
5) Zero monetization: Most of the companies focused on scale before revenue.

My reactions/key takeaways:

-Aspiring founders shouldn't be constrained by conventional wisdom or what the industry assumes won't work - assuming "easy to dismiss" things won't work usually shadow one's eye from larger trends and opportunities.
-If you're thinking about starting something, this probably won't help. The reasons for today's success are usually the reason for tomorrow's failure. 
-There is a survivorship bias in the study. There are probably millions of other companies fitting these 5 points who didn't make it. It would be interesting to do a study of companies that meet this criteria but didn't reach billion dollar valuations to evaluate the differences.
-Competitive markets should not deter founders from pursuing an idea - Facebook was certainly not the first social network, and Google was not the first search engine. Large, existing markets are usually ripe for disruption.