<i>But, a substantial portion of their revenues come from startups paying them for advertising</i><p>Total VC funding in the US is on the order of $50 billion per year.  If you assume 20% of that goes straight to advertising, which is unlikely, that&#x27;s $10 billion.  Facebook and Google sell about $100 billion a year worth of ads.<p>I would guess that Google and Facebook have less than 1% of their revenue concentrated in VC-funded startups.  They simply don&#x27;t have enough money to matter relative to the size of the broader economy.  It is not 1999 -- Yahoo is not making headlines with money it got from startups whose valuation is driven by Yahoo making headlines.<p>People in the startup community think the startup community is co-extensive with the tech industry.  AppAmaGooFaceSoft beg to differ.