The regulatory setting and growing worker mobilization in the digital platform economy have recently attracted much political and academic attention. However, the perspective of platforms as employers and their role in regulating the online market are less researched. This article contributes with a fresh perspective on labour platforms as potential employers and their various strategies towards collective bargaining. Empirically, the article draws on in-depth case studies of three labour platforms operating in Denmark, but choosing very different strategies towards collective bargaining. The study identifies four factors impacting their choice of strategy: platform ownership, existing sector-level agreements, growth rates and customer base.