I might be wrong, but I doubt the cap tables for the startups you listed are public. What the founders own is their own business. Sam's likely talking about a

I might be wrong, but I doubt the cap tables for the startups you listed are public. What the founders own is their own business. Sam's likely talking about a 'typical' exit for a startup that's taken venture capital - multiple funding rounds, reasonable valuations at each round. If your startup is a Facebook or Google and does a lot better than the 'typical' startup that exits (which just by getting to an exit has already done better than most), you can raise at better valuations and choose to sell less equity. If your startup manages to grow in a capital-efficient manner, you can also choose to sell less equity and keep more of it for yourself. That said, being irritated with Sam is just shooting the messenger - he's not lying to you. I certainly know of founders who came away with much, much less than 10% of their company. That also isn't necessarily a bad thing, since the stake they sold was used to get to an exit and expand their company. I'd certainly rather have 1% of a mammoth exit than 100% of a failure.