This paper provides new evidence on the development of online platforms and explores the emergence of new forms of work in the digital economy. Following the rise of platforms that match demand and supply of goods (e-commerce) and information (search, social networks), platform markets for services traded over the Internet (the "x"-economy) have grown exponentially in recent years. The paper analyses how online platforms affect the organisation of markets and work; discusses related opportunities and challenges for individuals participating in such markets; presents analysis of trends and effects of non-standard work in OECD countries; and identifies policy issues related to new forms of work. It finds that the transformative effects of online platforms may challenge existing institutions and might necessitate reviews of policy and regulatory frameworks in many areas. To further analyse such digital transformation, better data is needed on the effects of online platforms in all of these areas.