Digital citizen participation has attracted scientific interest for decades, particularly as participation platforms have been implemented and adopted in the public sector. Although progress has been made to overcome immature technology and low user-friendliness, digital citizen participation still faces challenges. The promising potential to enhance co-creation and create public value is often not realised. Various forms of citizen participation, including the digital platforms used, need to be further explored. In our theoretically informed case study, we use the 3A3 framework (Actors, Arenas, Aims), comparing two distinct digital participation initiatives within the same municipal context. Our contribution highlights how differences in rationale, structure, and interpretation of citizen input leads to divergent outcomes, either as optimisation (structured, goal-oriented participation) or innovation (open, creative participation). We also demonstrate the organisational challenges of adapting to open models of participation and how managed participation fits more easily into existing bureaucratic structures. For municipalities and policy makers, we offer practical insights on how to design and implement digital participation initiatives that are both meaningful and manageable.