Fog computing, a popular ambient computing technology has become a basic need for IoT as its characteristics outperform cloud computing in terms of cost, time and security. Fog lies between the cloud and the end users. The edge resources such as switches and routers could not cope up with the growing IoT needs and moreover, expanding fog resources require large investments from the perspective of the service providers. Instead, managing the need in the smarter way would bring profitable benefits. Research focusing on efficient resource provisioning to fog computing has come up with innovative solutions such as resource cooperation and resource sharing models. The main factor that drives resource sharing and resource cooperation is the user's participation in resource funding which is in turn influenced by incentives provided to the contributors. An effective incentive design to bring out the benefits of the crowdsourcing model successfully is essential. The existing crowdsourcing models for fog resource provisioning lacks an incentive mechanism to attract more contributors to fund their idle resources. Hence, an effective demand-based incentive mechanism is proposed to encourage users to fund their idle resources concerning to the demand in their location. Simulation is carried out and the results show that the proposed model is effective and the properties of the incentive mechanism are validated through evaluations. © 2019 - IOS Press and the authors.