Tracking the right metrics at every stage of the marketing funnel is essential for optimizing campaigns and driving growth. From initial engagement to incremental revenue, these metrics provide a clear roadmap for evaluating performance.
In season two of The Undiscovered Metric, we asked our podcast guests which metrics were the most important for marketers to monitor. Read on or watch our 2024 review episode below to find out what they had to say, and how these metrics stack up, from the top of the funnel to the bottom of the funnel.
1. Customer Engagement Metrics (Top of Funnel)
Engagement metrics are the foundation of any campaign. They help you understand if your audience is paying attention to your message and interacting with your brand. Strong engagement is a sign that your campaigns are resonating and setting the stage for conversions.
"If you have a strong enough concept of your buyer…engagement from that list of companies tends to be the leading metric. If you see that going well, it will break into revenue."
Tracking engagement specifically from your priority audience ensures your campaigns are connecting with the right people—not just generating random clicks or views. This focus early in the funnel helps marketers target effectively and refine messaging.
2. Primary Conversion Metrics (Middle of Funnel)
Primary conversion metrics measure the actions that represent meaningful engagement and progression through the funnel. In the middle of the funnel, these conversions often include form fills, resource downloads, or demo requests—actions that demonstrate interest and intent but don’t yet signal a purchase.
When asked about the most important metrics his clients focus on, Landon Perry, VP of Ad Measurement and Data Analytics at Green Line Digital, boiled it down to three core areas: primary conversions, cost per conversion, and conversion rate.
"99% of our clients are really focusing on those three: what's the primary thing we're trying to drive? Are we trying to drive downloads or form fills?"
Landon Perry, VP of Ad Measurement and Data Analytics at Green Line Digital
Tracking primary conversion metrics helps marketers understand whether their campaigns are successfully engaging prospects and nudging them toward a purchase decision. These actions may not directly generate revenue, but they signal the effectiveness of your campaigns in building intent and trust.
By knowing how much it costs to achieve a middle-of-funnel conversion and understanding the number of clicks needed to drive that action, marketers can refine their targeting, plan budgets more effectively, and scale campaigns with confidence.
Primary conversion metrics aren’t just about measuring engagement—they serve as critical markers that guide prospects from awareness to decision, ensuring that every step of the funnel contributes to your overall goals.
3. Cost Per Acquisition (CPA) (Lower Funnel)
CPA helps you understand how efficiently you’re converting prospects into customers. By breaking it down into cost per click and conversion rate, CPA provides actionable insights into where improvements are needed.
"CPA is defined by the cost per click and the conversion rate. Those are the two things that create CPA. As an advertiser, those are your levers to improve and change CPA."
Tracking CPA ensures that your acquisition efforts remain cost-effective while driving high-quality leads.
4. ROI / ROAS – Return on Investment / Ad Spend (Lower Funnel)
ROAS shows how much revenue your campaigns generate for every dollar spent, providing a clear view of overall efficiency. It’s one of the most universally tracked metrics for determining the financial health of a campaign.
"We look at ROAS in three lanes: cost, output, and outcome. How can we spend in the most cost-effective way? How do we ensure our audience is engaged with our ads? And how do we make sure they convert as much as possible once they land on our site or stores?"
Jeff Coleman, Leader of Digital Marketing Science at Carter’s
ROAS is vital for optimizing ad spend and ensuring campaigns generate the highest possible returns.
5. iROAS – Incremental Return on Ad Spend (Bottom of Funnel)
iROAS takes the concept of ROAS further by focusing on the incremental revenue generated by your campaigns. It helps marketers separate the baseline revenue driven by brand strength from the additional revenue directly attributable to advertising efforts.
"What you want to know as a marketer is, ‘What are we getting incrementally for our investment?’ So, that's what iROAS gives us. It gives us a true understanding of what is the incremental impact that every dollar is making on driving the business."
Jeff Coleman, Leader of Digital Marketing Science at Carter’s
iROAS provides deeper insights into the true effectiveness of your campaigns, allowing for smarter budget allocation and strategy refinement.
6. Audience Relevance (Across the Funnel)
Audience relevance ensures that you’re reaching the right people at every stage of the funnel. If your message isn’t connecting with the right audience, even strong engagement or conversions won’t translate into long-term success.
"I think the most important thing is to really be customer-centric, understand your audience, and get closer to measuring whether you're relevant or not."
Relevance ties all the metrics together. It ensures your engagement, conversions, and ad spend are driving value for the right audience, leading to sustained growth and loyalty.
Final Thoughts
These six metrics build on each other, creating a comprehensive framework for understanding marketing performance from top to bottom of the funnel. By tracking engagement, conversions, CPA, and ROAS—and ensuring your audience is the right fit—you can make smarter, data-driven decisions at every stage.
For more expert insights, check out The Undiscovered Metric podcast.
