(I don't plan to mention that every time I find a new one, but this is the most perfect example I've found since I thought of trying to detect them algorithmically.)
If a 3.25b valuation at Square's age is a huge miss, all but a handful of companies in history have missed worse.
Do you actually know anything about Square's "PR machine," or are you just assuming he has one because he's in the press a lot? I don't know myself whether for example they have an in-house group that does aggressive outbound PR, or whether they have an outside PR firm, or both, or neither. It's possible the answer is neither; I get mentioned in the press a lot, and YC has neither.