Earlier quoted context omitted.
Also a pg essay from 2010: https://www.paulgraham.com/yahoo.html >By 1998, Yahoo was the beneficiary of a de facto Ponzi scheme. Investors were excited about the Internet. One reason they were excited was Yahoo's revenue growth. So they invested in new Internet startups. The startups then used the money to buy ads on Yahoo to get traffic. Which caused yet more revenue growth for Yahoo, and further convinced investors…
That's not how Ponzi schemes work. Yahoo had a defacto _monopoly_ and the market had bad discovery leading to bad price information. There was no point at which the internet was /not/ worth investing in and everyone who had experience with it knew that. The real problem seemed to be that you can only put so much money into pets.com before it becomes stupid. You had more short term investment capital than could be _ef…
Words have meaning in context, and calling something a "Ponzi scheme" these days means any pyramid-like system that only works as long as new investors come to the table, because that new investor money is the sole source of gains for earlier investors. But once you run out of new investors, which is inevitable, the whole thing collapses. What pg described was exactly a Ponzi scheme in that sense, even if it wasn't a deliberate scam. And that's very different from other types of business ventures that eventually fail because of the more "normal" reason that they just don't gain traction.