Sounds to me like someone at Amazon is good at marketing. Let a few things go for an insane deal, knowing it will hit the front page of every blog. Then reap the rush of next years prime day with people scouring the site for pricing "errors". Pretty cheap and effective marketing. Kind of like a raffle but without having to get all the lawyers involved to make sure you comply with raffle laws.
Or someone on slickdeals is good at marketing because that's what half the article talks about. I'm surprised Amazon honored such a big price mistake. A few weeks ago, some Western Digital drives were priced incorrectly. About half off. Everyone got cancelations. And yes, I heard about it on front page of slickdeals...
Once the deal was caught by one of our mods, the site went into a frenzy. Unfortunately I was AFK during the deal, but this will go down as one of the best price mistakes of the year if not the best.