With a mobile wallet the process could be quite different. Consider this: you're walking past your favourite Indian take-away on the way home. As you walk past you get a text offering you half-price on your favourite curry. The next day you walk in and order the curry, paying by flashing the back of your phone at the point of payment with the offer applied automatically.

I saw an interesting news story this week in the New York Times on a retailer in the US that is refusing to stock the Amazon Kindle. The reason? Because customers are coming into stores, asking questions about the Kindle, getting expert advice from the in-store sales team, then walking away without purchasing and ordering online - usually direct from Amazon.

Why is it that a product or deal displayed in a retailer's store may not be available to buy online or vice versa? Or why is it sometimes not possible to return a product bought online to the same retailer's store?

Gathering data for tailored one-to-one messaging and smart marketing is rebooting retail on and offline, writes James Silver.