(CNN) -- As the legend goes, it all started with two Americans living in London in search of a good burger. Bereft of what they considered acceptable options, the pair decided to open their own American-styled diner with the food and attitude to match. They would call this nascent start-up the Hard Rock Cafe. Over the next two decades this famous old joint became a regular haunt for A-list musicians and a museum for rock star memorabilia. Today, it's a global industry with 180 venues in more than 50 countries, including outlets as far afield as Bahrain and Dubai.
@highlight
Hard Rock Cafe is expanding into Asia and the Middle East
@highlight
Company has more than tripled revenues since 2003
@highlight
Business now focuses on casinos and hotels as well as restaurants and music
@placeholder t-shirts and other merchandise still account for between 30% and 50% of sales at each destination after all.