I admit that Amazon doesn't take them directly, I have to buy an Amazon gift card from Gyft.com and then use it on Amazon. I can buy things on Amazon with Bitcoin, it just takes a few extra steps.
Fair enough. That's still pretty neat.
Why is it neat? Why take all the extra steps when you can just use your local currency? A currency that likely hasn't lost half its value in the last 2 months and didn't require a third party broker who took a slice?
And a gift card? How annoying. If I want something that is £7.49 what happens to my £2.51 change? Oh, Amazon hold that money for me offering no interest until my next purchase. What if instead I want to use that £2.51 to buy a cup off coffee? With regular cash, no problem.
The biggest problem with bitcoin, and it hasn't been addressed yet, is that it is only accessible to the technically astute. You can't have a currency that isn't accessible to everyone. Money as we know it, is recognised and used by everyone. Its an easier way to trade than barter, which is why we use it. Bitcoin isn't.
I'm sure Rushy will rush back saying how easy it is and that only a moron couldn't use it and blah blah, but its not as easy to use as cash. And there in, will lie its downfall.