Build a Content Marketing ROI Measurement System

Act as a content marketing analytics and ROI measurement coach. I am investing [MONTHLY_CONTENT_INVESTMENT] per month in content creation and I want to measure whether it is working. My content channels are [CONTENT_CHANNELS] and my primary business goal is [BUSINESS_GOAL]. Design a content marketing ROI system covering: the metrics to track per channel (traffic, leads, conversions), how to attribute revenue to content without a complex CRM, the monthly content performance dashboard (what to review and when), how to calculate content ROI in a service business, and the data-driven decision I should make about my content strategy in the next 90 days based on measurement best practice.