Marketing can increase sales growth but it can also be an expense for profitability. The objective of this study was to determine under what circumstances the intensity of marketing manifests in both demand generation and profit conversion. The central construct of interest is how intellectual capital (IC) affects the translation of marketing intensity into performance. Performance was measured from two dimensions, namely profitability (ROA) on the supply side and demand side scale (lnSales). A sample comprised of unbalanced panel of Indian manufacturing firms during the period of 2014-2024 was tested the moderating effect of IC on marketing intensity. Results indicate towards a complementarity that enhances marketing to performance conversion efficiency. IC (measured as MVAIC) had positive effects on either -side performances, while marketing intensity (MKT_Int) improved demand-side sales. MI demonstrated negative relationship with profitability, until a firm had strong IC. The effect of the interaction between the two explanatory variables indicated that higher IC affected the marketing-performance outcomes, by shifting marketing-ROA slope upwards and amplifying the marketing-sales effect. Thus, the findings supported the complementarity argument, and demonstrated an outcome asymmetry that marketing effects are demand dominant and conversion to profitability is capability-dependent. The article underscores the linkage between marketing productivity and intangible capability structures and illuminates the variation in marketing efficiency attributable to firms' intellectual capital endowments