You're Spending More on Paid Media, but Your Bidding Algorithm Can't See a Quarter of Your Buyers

Marketing budgets grew just 1.3% last year, the smallest rise since 2022, while 94% of CMOs say expectations from the top have risen sharply. Meanwhile, paid media spend is up 12.5% in two years and now eats up 31.4% of the average budget. This increase is often funded by cuts to martech and agencies. The logic is simple: if you can't grow the pot, put more behind the channel that scales fastest and reports easiest.

Here's what that logic misses. Google and Meta's bidding algorithms only optimize against the conversion signals you feed them, and most teams feed them digital signals only, like form fills, checkout completions, or chat starts. Phone calls barely register, and when they do, Google counts anything over 60 seconds as a conversion, full stop. A wrong number, a complaint, and a booked job all count the same. Which means that 12.5% increase in paid media spend doesn’t always yield concrete results.

Why Phone Call Conversions Need to Be Part of Your Paid Media Strategy

Marketing wants more leads entering the funnel, but if you can only see the digital ones, every audience, lookalike, and customer journey you build gets trained on that part of the picture. Pour more spend into it and you're not correcting the blind spot, you're teaching the model to find more people just like the buyers it already knows about, while the ones who call instead stay invisible. That's not a wider net. It's the same net, thrown harder, and yet teams still expect a different catch.

And those invisible callers aren't a rounding error. Nearly a quarter of UK consumers called a business specifically because they couldn't find what they needed online. 

Invoca's Lead Conversion Benchmarks Report shows just how valuable it can be to optimize for phone call conversions. The average business answers 56% of calls—38% of those are leads, and 42% of those leads convert. If you increase each of those benchmarks by just a few points, you can convert more phone leads from paid search and dramatically improve your ROI.

Case Study: Vivint Grows New Customers by 76% Thanks to Call Tracking

Vivint proved the value of optimizing for phone call conversions. Their callers convert at a 30% higher rate than form leads, but marketing had no way to trace a call back to the campaign, landing page, or device that drove it. Instead of asking for a bigger media budget, the team got visibility into which calls its campaigns drove, whether they were answered, and whether they converted, then reallocated its existing spend toward what the data proved was working. New customers generated by marketing grew 76% year over year, all by simply using better data. 

Case Study: Southern Sheeting Uncovers Customer Experience Issues in Phone Conversations

Tapping into phone conversations doesn’t just improve paid media returns—it can pay dividends for the customer experience as well. Southern Sheeting's Head of Marketing, Jo Morfield, learned this firsthand. Sitting next to the sales team at one depot, she could hear the rep's side of a call, but never the buyer's, and the other two depots were invisible entirely. She decided to onboard Invoca to fill this gap.

Within two months of getting proper visibility into both sides of every conversation, her team had analyzed more than 2,000 calls. They learned that two very different journeys were taking place inside their phone conversations: trade buyers who already knew what they needed, and retail buyers who needed more guidance. 

The retail buyers who required guidance often asked about one thing: fixings and accessories. This stood out as one of the biggest single drivers of inquiries, a topic that had never once surfaced in web analytics because it spans multiple product categories. She can now update FAQ content, product pages, and sales guidance to address these knowledge gaps and better serve customers. 

Beyond insight into which ads were driving revenue for the business, the team also gained insight into what buyers actually wanted to know, information no one in marketing had been able to see before. A complete view of what customers were asking allowed the team to provide a better customer experience, and meet people exactly where they were in their journey.

The Question to Ask Before the Next Budget Round

AI is an undeniably powerful tool. 70% of CMOs now call AI a top investment priority, and it already claims 15.3% of the average marketing budget. This technology can genuinely deliver the efficiency everyone's chasing, but only on the data it's given. Point a bidding model, a forecasting tool, or an AI agent at the same digital-only picture, and it optimizes based on incomplete data. Southern Sheeting's AI only found the gap in fixings and accessories because it had the call data to look at in the first place. Without that, it would have had to operate on guesswork.

So before your next budget round, ask this: Is the real problem a lack of spend on digital campaigns? Or is it that a quarter of your buyers picked up the phone, but you’re not able to see what happens when they do? That's the actual gap. Not spend or sophistication, but visibility.

Want to see how Invoca can help you improve your paid media ROI? Request a demo.