B2B marketing effectiveness is harder to measure than B2C with immediate conversion rates, because sales cycles are long and multiple decision makers are involved. Track results across three layers: First layer is reach and traffic—search rankings, website visitors, content readership, and social media impressions. Second layer is engagement and intent—how many people fill inquiry forms, download materials, and how long they stay. Third layer is business results—how many inquiries convert to orders, average deal size, and customer retention rates. Track all three layers; only looking at final sales numbers risks missing upstream issues, while tracking only traffic doesn't clarify where money is spent or if it's working. Establish a regular monthly or quarterly review cycle, comparing each metric against marketing investment to determine which channels deserve increased spending and which need adjustment.