This seems like a loose interpretation of the WSJ article, which estimated roughly 300k from both digital retailers (Amazon and iTunes). I don't see how you can go from that to 300k from Amazon alone. Either someone's sources are wrong or the estimates for the total sales for the week are simply too low.
And no matter how many times some of you wish to ignore it, this was Amazon's decision, as stated numerous times by Billboard, NYT, WSJ, etc. Interscope cannot force a company to sell something for a loss. Not that Interscope doesn't love it - they get more sales, and they still sold the album at wholesale price. Why wasn't your fave's album chosen as this type of loss leader? Well, that's just one of the many perks of being the biggest pop star in the world.
