Crowdsourcing is usually implemented using an intermediary organization or directly coordinated by solution seekers. For those using an IT-based crowdsourcing intermediary, the important factors of intermediaries that impact the crowdsourcing outcome are yet unclear. In addition, little research was conducted on how to design a crowdsourcing intermediary that can address the combined challenges of considering different cognitive demand levels of solution providers' contributions, combining contributions and evaluating contributions. This paper identifies three important factors and provides a novel design of crowdsourcing intermediary to cope with these challenges. This study uses a case that focuses on how to assist small and medium businesses (SMBs) to develop their service imageries in triggering service innovation and designing their service experiences as to fulfill the desired outcomes of customers. Through the case, the benefits of our crowdsourcing intermediary design are demonstrated and justified. The three important factors are the crowdsourcing intermediary knowledge base, generative networks and empowerment of crowd members. This study shows that the crowdsourcing process can facilitate achieving a higher chance of attaining creative solutions for SMBs' innovation problems when the three factors are well incorporated and managed within the crowdsourcing intermediary design. This study also presents a novel design of crowdsourcing intermediary that can address the combined challenges of coping with different cognitive demand levels of crowd members and combining and evaluating crowd members' contributions, in order to attain impactful crowdsourcing outcome.