Semiotics is the study of signs, symbols, and signals. By deconstructing culture to determine underlying codes, it tells us how meaning is created. It is behind some of the most successful brand campaigns and has contributed to the critical insights behind new product launches. Many companies such as P&G and Nestle swear by it as part of their innovation process.
For more detailed information on how semiotics can be useful for brand development, marketing communications, and design & new product development, check out this PDF.