Daniel Ehls analyzes the impact of contextual factors on attracting volunteers into open initiatives. He answers challenging questions like Why do users join one community over another? and What are attractive conditions for user and open innovation? With a discrete choice experiment, Daniel Ehls identifies openness trade-offs and joining preferences contingent on access, usage and sponsorship. Also, he reveals causes of taste heterogeneity and shows how context and personality determine joining decisions. Management insights target organizational behavior, e.g. how the governance structure affects user actions, and competitive strategy, e.g. how to source external distributed knowledge.   Contents n  Attracting Members in Open Institutions and Communities n  User Behavior, Volunteering, and Individual Traits n  Open Innovation, Open Source, and User Innovation n  Organizational Design, Community Optimization, Fostering Collaboration   Target Groups ·         Researchers and students in the field of open and user innovation ·         Entrepreneurs and consultants striving for new opportunities in product development and value capture, Decision makers and practitioners in the area of corporate development, organizational design and strategy   The Author Daniel Ehls studied Technology Management and worked as a management consultant before he gained his doctorate degree while working with Prof. Dr. Cornelius Herstatt at the Institute of Technology and Innovation Management, where he is now a postdoctoral researcher.