Do rebranding exercises actually work? I guess that they must because otherwise no-one would bother, but I still goggle at the millions paid to agencies full of sharp-suited, gimlet-eyed advertising executives to fractionally change a logo here, alter a tagline there. And I do know that sometimes they really don’t work. You may remember that to bring itself into the new millennium the Post Office decided to rebrand. After two years of consultancy it changed its name from Post Office, which everyone knew and understood, to Consignia, which meant nothing to anyone. Sixteen months later they changed it back again. The adventure cost the Post Office £2m, its chief executive’s job and an incalculable amount of reputational damage.