The document provides guidance on demonstrating return on investment (ROI) from Marketo in three ways: tactical, strategic, and organizational. Tactically, ROI can be shown through A/B testing of email sends and retargeting campaigns. Strategically, engagement programs can be implemented to nurture leads based on behaviors and preferences. Organizationally, aligning Marketo usage and reporting with sales helps prove marketing's impact on revenue by connecting leads to opportunities and revenue. The document includes case studies and lessons learned around implementing these approaches.