Online video advertising has grown exponentially since 2009, when Forrester first assessed the state of online video advertising in Europe. Consumers' video consumption has grown rapidly, publishers' offerings for video advertising have matured, and marketers' budgets for video keep climbing. In this study, we assess online video advertising experience on high-traffic European publisher sites, on desktop, and on mobile browsers and apps. The report highlights current trends in online video advertising and focuses on the practices to encourage — and avoid — when designing effective online video advertising campaigns.