Interesting. You see I really like the purchase tracking. Over time it makes my shopping easier, because the system knows what I'm likely to need. Things like re-ordering easily is also brilliant, because I can never remember what deal on batteries I got 4 months ago etc.

I would probably never buy chemicals and nunchucks on Amazon for that very reason. :) The thing is, Amazon's strengths are in the sum of the parts, rather than any one single bit. Put it all together and you basically have an absolutely awesome retailing machine.

I remember standing in a now defunct (!) camera chain shop in town to buy an SD memory card. It was something like £60 which seemed a little expensive to me, so I dragged out my phone and did a quick check on the Amazon app. It was £16. I was so outraged at the delta, I went over to the assistant and told him. He couldn't have cared less.

So I went outside, stood on the sidewalk and bought the card from Amazon in 40 seconds using the app. It arrived the next morning. The camera chain went bust this year.