Amazon has added barcode scanning to its Apple iPhone shopping app. It is an amazing feature. Here’s why.

Among the questions that shoppers ask themselves, two of the biggest ones are first, is it any good; and second, is it good value? Barcode scanning helps with both of these. The scenario is that you are in the shop looking at a book, CD or DVD – or almost anything really, from kettles to MP3 players – and you wave your iPhone over it. Up comes the entry for that item in Amazon’s store, where you can see the rating, read customer reviews, and check the price both new and used.

OK, there is a little bit more involved than waving the iPhone, but not much. Here is how it works. Tap the Amazon app on the iPhone, then Search.

 

Tap Scan a barcode and hold the iPhone over the barcode.

You adjust the size and position by moving the iPhone until the code is roughly central between the guide lines. At this point, the guide lines turn green.

No need to tap; the app will now look up the item and show you the results. Tap the right-pointing arrow for more detail.

Confession: I am sufficiently an Amazon addict that I have done this in shops even before the advent of the barcode feature. One reason is price-checking. We all know that you pay a premium for the instant gratification of bricks and mortar shopping; but how bad is it? This will tell you instantly.

That might not help if you need a gift at the last minute, but the reviews might. I use this for video games, or for CDs that I have not heard or DVDs/Blu-rays that I have not seen. It has saved me from some expensive mistakes.

Of course reviews are subjective and some are likely planted by publishers, authors or competitors; but there are usually enough to give you some idea of the range of opinions.

It is also handy for electronic devices. Is that MP3 player any good? How does that iPod dock sound?

When I was at school we learned about the concept of perfect competition. One of the requirements for perfect competition is perfect information – for example, knowing the price charged for an item in every outlet which sells it. We are a long way from that, but thanks to the Amazon marketplace, where third-party sellers compete, we are closer than we were. The barcode feature in the Amazon iPhone app makes it easy to access that information while shopping, which is a big feature.