Consider the different strategies adopted by the two leading companies in the pet-food industry: Nestlé Purina PetCare, the largest player in North America; and Mars Petcare, the global leader. The companies have defined very similar purposes for themselves—“Better with pets” (Purina) and “A better world for pets” (Mars Petcare)—and both want to develop new products that will help customers improve their pets’ health. But Purina has continued to focus on the pet-food playing field and is applying purpose in some inspiring social initiatives, whereas Mars Petcare is using purpose to propel its expansion in the broader field of pet health. Insights by Professor Thomas Malnight