Over the past 20 years, designer Christian Louboutin has built a fashion business based on one of the most sought-after shoe brands worldwide, boasting a sales increase from more than 300,000 pairs sold in 2009 to 700,000 in 2011. His designs reached a new level of recognition this year, when some of his most exquisite, quirky and famous shoes were exhibited at London’s Design Museum, where a retrospective of his work attracted more than 38,000 visitors in the show’s first six weeks, setting a new attendance record for the museum.

Clearly, people like Christian Louboutin shoes and their distinctive red soles — a lot.  As it happens, some other shoe designers and manufacturers also like the concept of red-soled shoes, and this is where the situation becomes more complex.