There are a bunch of these &quot;quiet unicorns&quot; sitting around, getting little SV press but lots of money and lots of impact.<p>Another one that often sticks out for me is WordPress.  I remember running some analyses over the whole web (first within Google as a side-effect of some work I was doing there, and then after I left Google with the Common Crawl corpus) that indicated that roughly 10% of the web is Wordpress.  That&#x27;s <i>billions</i> of sites.  As a proportion of content created, they&#x27;re bigger than Facebook and bigger than Twitter.  But because they&#x27;re privately held and have taken no outside capital, they have zero incentive to publicize this.  I&#x27;ve heard of people becoming millionaires <i>writing WordPress plugins</i> - not even working for them, but just contributing to the ecosystem.<p>GitHub was in this category until they took VC from a16z, as well, and Atlassian before they went public.  I sometimes wonder how many of the &quot;little&quot; sites I use routinely (eg. bahiker, PadMapper, Paletton) secretly generate huge revenues.  When formerly-unfunded-but-widely-trafficked sites like PlentyOfFish or Imgur get valuation events, they&#x27;re often stupidly high (eg. $575M for PlentyOfFish and $200M+ for Imgur).