This book combines theoretical background and empirical analysis in order to create an understanding on the relationships between mass customization process and success factors necessary to make it work. We determine which mass customization approach is most commonly used among MC companies. Mass customization theory is thoroughly covered in the literature review. We includes topics from both international business and marketing fields, such as: internal and external success factors; MC levels and approaches; flexible manufacturing systems, and perceived added value though customer integration. This work focuses on mass customization start- ups hence its managerial implications can be seen as particularly relevant to new ventures that consider entering the ever-growing mass customization arena.