"But Apple couldn’t enter the ebook market while charging consumers five dollars more per unit than its biggest competitor was. It needed some assurance that no one would have a cheaper product than it had. So it made a deal with five of the Big Six publishers (Simon & Schuster, Penguin, HarperCollins, Hachette, and Macmillan; Random House, then the biggest trade publishing house, abstained): They could all sign on to Apple’s agency model, as long as they guaranteed that they’d also use that same agency model with every other retailer they worked with. That way, Amazon, too, would be forced to sell its ebooks for $14.99 — and if it refused, publishers could withhold their ebooks from Amazon and make them exclusive to Apple.
Publishers agreed to the deal. And just like that, everything changed."