Call CRO: The untapped lever to lower CPL and boost ROAS

In call-centric industries, every conversation carries weight. You can invest heavily in generating leads, but if those high-intent calls don’t convert, it eats into budgets fast. That’s where call CRO (call conversion rate optimisation) comes in. By focusing on actions that deliver more positive call outcomes, marketers can dramatically reduce CPL on calls and increase ROAS, all without spending more on media.

What is Call CRO?

Call CRO is the process of optimising sales calls so more of them end in valuable outcomes like a purchase, a booking, or a request for a quote. Think of it as traditional CRO, but tailored to phone calls.

Instead of only analysing online journeys, call CRO looks at what happens when a customer actually picks up the phone. Did they reach the right person? Was stock available? Did the conversation inspire trust? Optimising these moments helps ensure every call delivers value.

How does Call CRO reduce CPL?

Driving calls through paid ads can be expensive. If only a small percentage of those calls convert, your cost per lead skyrockets. But when more of your phone leads turn into sales-ready opportunities, your CPL naturally falls.

For example, if 100 paid calls generate 20 conversions, you’re paying for 80 wasted opportunities. Improve that conversion rate to 40%, and suddenly the same budget delivers double the outcomes. Call conversion rate optimisation ensures you’re not just paying for calls, but paying for outcomes.

How does Call CRO increase ROAS?

Paid campaigns live and die on their return on ad spend. You want every click that drives a call to result in revenue. When conversion rates on calls improve, so does the ROI of your campaigns.

Instead of pushing more budget into media spend, call CRO lets you maximise the value of the calls you’re already generating. That means every extra sale, every booked appointment, and every confirmed quote increases the return on the same ad investment. For marketers under pressure to prove results, that’s a powerful lever.

Why should marketers care about call CRO?

Budgets are tighter than ever, and marketers need to defend every pound they spend. If you’re investing in campaigns that drive phone calls, being able to prove those calls convert is vital.

High conversion rates don’t just demonstrate ROI; they also show that your targeting is working. You’re reaching the right people at the right time, with the right message. That makes it far easier to secure ongoing investment in your paid campaigns, because leadership teams will see the tangible value marketing is delivering.

Put simply: if you’re not optimising the conversion rate of your calls, you’re leaving money on the table.

What gets in the way of call conversions?

Even with strong intent, not every call ends positively. Common barriers include:

• Stock availability – The product isn’t available, or appointments aren’t open.
• Messaging clarity – Customers don’t fully understand the offer or its value.
• Targeting mismatch – Calls come from the wrong type of lead.
• Sales handling issues – Agents aren’t aligned with campaign messaging or miss key opportunities.
• Trust and readiness gaps – Callers aren’t convinced, or aren’t quite ready to buy.

Individually, these issues might seem small. But collectively, they can add up to high CPL and disappointing ROAS.

How to deliver better call CRO

The key is visibility. You need to know why high-intent calls aren’t converting before you can fix the issues. Traditionally, that meant listening back to hours of calls, a time-consuming and unscalable task.

Today, AI tools like Infinity’s Conversion Barriers make it possible to analyse call data automatically and highlight exactly what’s stopping leads from converting. Whether it’s unclear offers, poor lead fit, or missed objections, you get actionable insights that show you where to focus your efforts.

This isn’t about adding more tech for the sake of it. It’s about giving marketers and sales teams a clear view of what’s going wrong and how to fix it. That way, you can stop wasted spend, align teams, and optimise campaigns for outcomes.

Turning barriers into opportunities

When you understand what’s stopping conversions, every challenge becomes a chance to improve. Stock issues? Adjust your campaigns to pause ads for unavailable products. Confused customers? Refine your messaging and landing pages. Missed sales opportunities? Give sales teams the insight and training they need to handle calls more effectively.

The beauty of call CRO is that small tweaks can have a big impact. By removing just a few barriers, you can transform performance across CPL, CPA, and ROAS.

For marketers in industries where phone calls are central to the customer journey, call CRO is one of the most overlooked levers for growth. It ensures that every hard-won lead has the best chance of becoming revenue.

Instead of pouring more budget into generating calls, focus on converting the ones you already have. By identifying and removing the barriers that stop high-intent calls from converting, you’ll lower CPL, boost ROAS, and make a stronger case for future investment.