Case studies are marketing components used to analyze and communicate how you perform a certain work. It should describe the process and methodology used to solve a specific challenge, resulting in a set of benefits. A great case study really helps potential customers to understand what they can expect - and sometimes act as awesome inspiration and education for others. Here are a few impressive examples.
Case studies put context around the beautiful portfolio pictures so common in an agency's gallery. Anyone can create pretty pictures. The question of business problems and the ROI generated is where the rubber meets the road.
Via Hannes, Brian Yanish - MarketingHits.com