Limitations of the Marketing Mix Framework

The marketing mix framework was particularly useful in the early days of the marketing concept when physical products represented a larger portion of the economy. Today, with marketing more integrated into organizations and with a wider variety of products and markets, some authors have attempted to extend its usefulness by proposing a fifth P, such as packaging, people, process, etc. Today however, the marketing mix most commonly remains based on the 4 P's. Despite its limitations and perhaps because of its simplicity, the use of this framework remains strong and many marketing textbooks have been organized around it.

source: http://www.netmba.com/marketing/mix/