Open innovation describes an innovation paradigm shift from a closed to an open innovation model (Chesbrough, 2003). With this idea, the term “open innovation” became one of the most common used buzzwords of recent years, with a plethora of research. These days, many companies are already using open innovation principles in practice as well, especially when it comes to the integration of customers. However, the concept has been criticized for being too prescriptive and for offering little new to innovation research or practice (Trott and Hartmann, 2009). For instance, the lead-user concept (von Hippel, 1988, 2005) became one of the most important trends in innovation management in the last ten years, but questions arise whether open innovation is anymore than the lead-user concept (see IJIM Special Issue on User Innovation, 2008, 12(3)). Hardly anybody outside a company knows its products and processes better than its suppliers (Bessant, 2003; Petersen et al., 2003; von Hippel, 1988). Research confirms that intensive integration of suppliers in the value creation process positively influences the success of the company, particularly in highly competitive industries (Wingert, 1997). This is a result of the progressing reduction in the depth of value creation of manufacturers and the increasing transfer of know-how toward the suppliers. In multilevel business-to-business relationships, the suppliers often have the best or the only access and comprehensive knowledge about the end users (Groher, 2003). A practical example for supplier integration is the use of guest engineers (Maylor, 2001). Therefore, suppliers determine the scope of possible innovations, which most companies do not actively use, yet. The main risk for suppliers is the danger of releasing or using confidential expertise gleaned from other sources, thereforereciprocal trust is critical for this to work (Groher, 2003). Instruments, such as the continuous International Journal of Innovation Management Vol. 14, No. 4 (August 2010) pp. v–vii © Imperial College Press DOI: 10.1142/S1363919610002842