Some things don’t change much at Hard Rock Cafe. Half a century after the opening of the first restaurant on Hyde Park Corner, the burger remains the No 1 seller on the menu, customers queue up to buy a branded T-shirt and they stand in front of Eric Clapton’s guitar to have their photo taken.

“I always say it’s hard to go to an airport anywhere in the world and not find somebody in a Hard Rock shirt,” Jim Allen, chairman of Hard Rock International, said. “There really is a global following who travel the world collecting Hard Rock merchandise.”

It is a successful formula. The retail outlets linked to Hard Rock cafés and hotels generate 30 to 35% of a site’s gross revenues.

To read the full story in The Times please click here (subscription required)