The author thinks that it was just "PR and faffery", while discounting the actual value of PR and faffery. Never discount these things. MySpace was practically built on it.

Yes MySpace was created by marketing people, but that's the reason for both its initial rise and ultimate stagnation. Marketing people think "features" is the name of the game. Zuckerberg, like a good nerd, had the understanding that "platform" is really the name of the game.

Plus Zuckerberg's massive anti-privacy bias caused him to push the product in the right (superior product/market fit) direction in the face of significant user complaints (i.e. beacon).

And the speed at which facebook has been able to re-invent itself multiple times (e.g. platformization and twitterization) has been very impressive.

Exactly. "PR and faffery" are the secret sauce that will make or break your business. You can have the best product in the world, but without "PR and faffery" you will never get beyond a handful of early adopters. More than that, any site that looks like it has become successful without "PR and faffery" has just done the "PR and faffery" in a subtle way so that it looks like it has not happened!

Tautology? You've just defined a successful site as one that used PR and faffery to succeed (even if we can't see it), making it impossible to argue otherwise.

You can argue all you want! I have just expressed my honest belief that all successful sites use "PR and faffery" in some way or the other, even if its not obvious.