The volatility isn't a problem at all for any store to start accepting Bitcoin. If we look at how the far majority of the stores accept Bitcoin, then it's through third party payment processors who convert all Bitcoin sales directly into fiat. Stores don't have to deal with the volatility since it's the 'problem' of the payment processor that they use at that point. I am certain that Amazon is well aware of how things go in this market, but they, whatever their reason may be, have no interest in accepting Bitcoin as payment option. So no, no store accepting Bitcoin through these third party services will end up in the red because of the volatility....