The digital environment contains an increasing number of effective artificial solicitations of consumers’ attention that influence them to take transactional decisions that may go against their best interests. Unfair business-to-consumer commercial practices like dark patterns and manipulative personalisation may jeopardise consumer trust in digital markets and exploit consumer vulnerabilities. These practices call for an investigation of the market situation and a profound reflection on whether the existing EU consumer protection framework continues to meet these challenges. A key challenge is that such practices often operate in a blurred area between legitimate attempts at persuasion and illegitimate manipulation techniques. The research conducted for this study shows that dark patterns are prevalent and increasingly used by traders of all sizes, not only large platforms. According to the mystery shopping exercise, 97% of the most popular websites and apps used by EU consumers deployed at least one dark pattern and the most prevalent were (1) hidden information/false hierarchy, (2) preselection, (3) nagging, (4) difficult cancellations, and (5) forced registration. The prevalence of dark patterns nonetheless varies between different types of websites and apps. For example, countdown timers or limited-time messages are quite prevalent on e-commerce platforms, while the use of nagging is more customary in health and fitness websites/apps. In general, the prevalence levels are similar for mobile apps and websites, as well as across Member States and EU/non-EU traders.