Sony is shipping its Bravia X9 line of 4K TVs in the UK this week, and it wants to convey the advantages of all those extra pixels. The solution? Advertising that's as finely detailed as the screens themselves. It's putting micro ads on the fingernails and uniform of tennis player Anne Keothavong as she makes her way through Wimbledon, showing how the extra detail pays off. Few of us will get to see the ads in full clarity, however -- while Sony and the BBC are recording some of the event in 4K, they're playing that footage at an experience zone on the Wimbledon grounds. We're not looking at a decisive marketing coup, then, but those left squinting at home will at least know what they're missing.