A $300m Bootstrap Launched by a Teenager
mixergy.com
mixergy.com
This gets murky with private firms, since revenue isn't typically shared, and even more so with startups where so much of the value is based on future, projected earnings.
In general, though, I'd say the nomenclature more commonly refers to revenues and not 'valuation'.
But I was clear in the post that my research lead me to believe that the number originally came from the founders.
We'll never know for sure until they sell, but the achievement is impressive from everything I saw.