The document is a case analysis of Omnicom Group (OMC) conducted by MBA students for a class on Return Driven Strategy. It provides an overview of OMC as the largest advertising and marketing holding company generating $12.6 billion in annual revenue from over 5,000 clients in 100 countries. The analysis examines OMC's business model, growth strategies, and risks including loss of key clients or personnel and increased competition in a consolidating industry.