This is perfect use of the 7th mass media. Tesco's the biggest UK supermarket chain, has released a shopping assistant application. It starts out very innocently. It helps you organize your shopping list. And every shopper carries the phone in the pocket, it is a good shopping aide. But then it gets magical. You tell it which Tesco store you intend to shop in - or you ask the network to pick this store, where you are at the moment (which the network can identify easily from rough positioning of 'radio triangulation' without needing a GPS unit on the phone - and then the magic happens. The Tesco shopping assistant will re-arrange your shopping list items, by the order of the items in the aisles in the store, ensuring you the shortest path through the store to your own shopping.
Its like the phone reads my mind and helps make my life easier. Who doesn't want this? It won't prevent you from still looking at other aisles if you feel like wandering in the store, but you can get through the store the fastest, using this method.
And now the clever bit. Tesco's has already asked you permission to market to you. And it has your profile, it knows what you buy and don't buy. It won't show you any ads you don't want. But it can now offer you targeted ads and coupons, based on exactly what you like (and its near rivals). So, Tesco's knows that Tomi Ahonen is a Pepsi guy. Then that Tomi Ahonen is nearing Tesco's store number 124. Why not ask Coca Cola to serve Tomi an ad for 2 for 1 purchase of Coke. But as Pepsi knows Tomi doesn't buy diet stuff, it knows also to tell Coke to serve Tomi an ad for real coke, not any rubbish diet coke that he wouldn't even buy from Pepsi. Brilliant. And Tesco's won't release my name to Coke, no spam from Coke, Tesco's owns this relationship and will nurture it. They won't let a milk brand or beer brand or orange juice brand serve me ads, based on my Pepsi purchase pattern.. I love it! Its my fave story of mobile marketing currently.