GIVEN a fair wind, this summer should see a cable car running over the River Thames, connecting Greenwich to the Royal Docks in east London. The “Emirates Air Line”, named after the Dubai carrier, has already altered one familiar feature of the London landscape. For the first time since its creation by Harry Beck, an engineer, in 1931, the London Underground map shows a station that carries the name of a corporate sponsor. Two stations, in fact (see picture).

This feels like a minor commercial encroachment. Dubai's metro system has sponsored stations: a passenger can ride from Nakheel station, named after a property developer, through First Gulf Bank to Emirates station. Many of the stops on Las Vegas's monorail are named after casinos. But London is not Dubai or Las Vegas. Its two sponsored stations may be renamed as the market dictates: the Emirates deal lasts for ten years.

Still, the arrival on the map of sponsored stations fits into a pattern of growing commercialisation on the Tube. In the financial year 2010-11 Transport for London brought in £107m ($166m) in advertising revenue. Although that represented just 2.7% of its overall revenues, it was twice as much money as the Tube operator had raised five years earlier. CBS Outdoor, which has signed a multi-year deal with the Tube, has amassed a network of 1,200 digital panels on escalators and 126 projectors that beam adverts across tracks. Station “dominations”, where a sponsor takes every advertising spot in part of a Tube station, are becoming more popular. The arrival of underground Wi-Fi, this summer, will make digital shopping easier.

Christian Wolmar, a transport historian, points out that there has been advertising on the system since its earliest days: photos from the late 19th century show cards inside train carriages advertising domestic products. In some ways the Tube was far more open to private enterprise than it is today. The lines were at first run as distinct enterprises. For a spell, different companies ran the clockwise and anti-clockwise trains on the Circle Line, even maintaining separate ticket booths. The system may be burrowing back to its roots.