but that doesn't require Apple's participation in the collusion The kink that I think you may be missing is that the agency model dictates the retail sale pric

but that doesn't require Apple's participation in the collusion The kink that I think you may be missing is that the agency model dictates the retail sale price and the retailer profit margin. The agency model sets the price the publishers sell to the retailer at and the price that the retailer can then sell the goods at. So retailer A and retailer B can't really compete against each other on price because they're both locked into selling at the same price. If Publisher A and Retailer A collude to their mutual benefit, Retailer B can become royally screwed. [Edit: This Charlie Stross post talks about the different pricing models in the context of last year's Amazon/Macmillan kerfuffle http://www.antipope.org/charlie/blog-static/2010/01/amazon-macmillan-an-outsiders.html http://www.antipope.org/charlie/blog-static/2010/01/amazon-m...]