We’re all used to seeing targeted advertising on the Tube. Go into the West End, and the escalator walls will be papered with invitations to go to a nearby theatre, and so on. Now, however, targeting’s gone on over-drive. Advertising on London Underground is handled by Exterion Media, which has just set up a partnership with Telefónica UK. Exterion claims to be Europe’s largest privately held Out-of-Home (OOH) advertising business, while Telefónica UK is one of the world’s biggest telecommunications companies. The basis of the new relationship is that Telefónica will take information from their customers about their purchasing preferences and their travelling habits. The information will be anonymised and handed over to Exterion. Thus if Telefónica can work out that on weekdays you travel from Whitechapel Tube to Monument, and that you like to order Domino’s takeaway pizzas, it will tell Exterion that someone using Whitechapel and Monument Tube stations likes Domino’s pizzas. Exterion then tells Domino’s that pizza eaters are using the station and Domino’s pays for advertising there in the hope that when you see a picture of your takeaway of choice, you’ll want one and order one on your way home. There are three kinds of problem with this approach. First, a company is taking data for a purpose other than that for which it was intended. When you phoned Domino’s, you wanted a pizza within 45 minutes – not to have an input into what you looked at while you’re on the Tub escalator. Second, it’s not an exact science. If you, and the other Domino’s afficionado’s, if your Tube station has a concentration of them, change jobs or eating habits, your historic data becomes irrelevant – but that will take a while to show up and Experian won’t be hot footing it down to your Tube station to change the advertising posters until the changes in your lifestyle filter through. Experian will be paying Telefónica for this data – which means you will be footing that bill from your Tube fare. Did anyone ask you if you wanted to pay it? Did anyone ask you if you wanted to pay for organising the advertising preferences in a way that will fall out of date? Third, information advertising is one thing: remember to get your flu jab; take your folic acid if you’re trying to get pregnant; there’s a new ingredient in Special K – that’s all providing us with information and useful reminders. The second kind of advertising attempts to create a demand where none previously existed. In that case, you’re heading home to a lean chicken salad when you are tempted by the sight of pizza; or your children are reminded of the latest Disney film or new brand of sweeties and feel they should do what the adverts tell them (and nag mum to provide). Advertising: there’s always someone paying the cost. And it’s usually you.