Strategic Digital Marketing Capability and Sustainability Engagement in European SMEs: A PLS-SEM and Fuzzy Cognitive Map Approach

European SMEs are expected to digitalise and cut their environmental footprint together. Research on this twin transition has focused on production, not marketing. We ask whether digital marketing capability is associated with environmental engagement, eco-innovation, sustainability strategy, product innovation, and growth ambition. The capability is a formative composite of cross-border online selling, innovation in selling methods, and big data analytics. We estimate partial least squares structural equation models on 10,778 EU27 SMEs from Flash Eurobarometer 486 (5000 bootstrap resamples). A fuzzy cognitive map seeded with the estimated paths simulates eight scenarios. All hypothesised direct paths are positive (p < 0.001), led by product innovation (0.268) and green engagement (0.202). Eco-innovation carries 28% of the association with strategy adoption. For eco-innovation and strategy, the association runs through selling innovation and analytics, not online sales. The moderation effect is negative: growth ambition weakens the link between capability and green engagement (−0.026, p = 0.017), consistent with, but not proof of, competition between commercial and environmental goals. In the simulation, a 50% rise in adoption of the three activities raises the share of SMEs with eco-innovation by 2.3 percentage points. If these associations reflect enabling effects, support could target analytical and selling capability over channel presence.