The other day a man who had recently bought a famous fashion trademark, Mainbocher, with interesting plans for reinvention came to see me. It turns out he bought the marque from a man whose father had been very canny in snapping up these defunct-but-aromatic names, and still in the vault is Paul Poiret, among others. Which means that post-Worth and Vionnet and Schiaparelli, there are still a bunch of once-famous fashion houses that are potential relaunches. But should they be? Increasingly, I think that the old arguments in favour no longer hold true, largely because of the Brave New World of social media.