This paper introduces an on-demand data monetization model for IoT de-vices. The Internet of Things (IoT) allows millions of devices to be connect-ed to the internet and share data with the world. This creates a market for IoT device owners to monetize the data produced by their devices. Block-chain technology came to the world with the promise of providing a trust-less and secure data and money exchange model. Our proposed model uti-lizes blockchain technology and smart contracts as a suitable candidate for IoT devices to share and monetize data on top of it. It uses the Blockchain infrastructure as a data storage and money exchange service. This model al-lows anyone who owns a device capable of producing data to be able to monetize this data easily by offering and selling it to others. On the other hand, it allows smooth data access and purchase for interested buyers.