One of the big selling points people often push about QR Codes is the fact that you can make them look very different before they stop working. This is down to the large amount of redundancy, 30%, which allows for impartial reads without losing data. It is also this which makes it ideal for postering or to be scanned by mobile phones which do not always produce the clearest image.
However once people start putting their logo in the middle of the QR Code, often by this point their logo is only 10 pixels wide so fairly pointless, it then means that the image to capture the barcode must be perfect. Now this can be hard unless there is perfect light and people with shaky camera phones are willing to take the appropriate time.
What is more it actually makes the barcodes harder to identify! If you want more people to scan your QR Codes, as is usually the case, there is nothing wrong with a black and white block looking distinctively like a barcode. People instantly know what they are expected to do; in advertising you must remember the inherent laziness of the consumer since they do not have a vested interest in completing the desired action.
Anyone else agree with this or am I just being grumpy?