631/48000=?
1,15/34=?
Those are your margins. If they are less than T+400bps[1] you are "losing money" for investors. Unless, there are other investors looking to take the stock off your hands.
It's hard to imagine where all those investors think the extra profits will come from. Do they expect Amazon to suddenly announce one day that it has finished trying to grow, and will be raising prices immediately? Or do they think that eventually, every single one of its competitors will have given up, and folded beneath the company's relentless expansion?
Unless you have a real answer for this, you are betting on the greater fool theory. Of course, you may have a better answe than this. [Digging around a bit, it seems to (/may) be tax avoidance. Amazon is eating fulfillment costs in lock-step with its increasing gross profits on product sales].
[1] technically, multiplied by another factor of around 1.8, which is the sales/asset ratio. This number appears to be <6%. http://static.cdn-seekingalpha.com/uploads/2013/1/8/2164901-...