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Meta Does Best, But Google Overperforms: A Lead Forms Comparison
Hypothesis
We want to determine whether Google Performance Max is efficient enough at native lead-form acquisition to warrant inclusion alongside Meta in future campaigns. We expect Meta to deliver lower CPAs and will consider PMax viable if its CPA runs no more than 50% above Meta's and its lead quality (measured by downstream email open rate) falls no more than 10 points below Meta's.
Experiment Design
We ran two campaigns on Meta and Performance Max targeting similar audiences over the same four-week window, with both campaigns past their learning phases. We tracked email open rate alongside CPA because lead forms get a bad rap for delivering cheap leads that don't go anywhere. Looking at downstream engagement tells us whether the leads were actually worth following up on, not just inexpensive to acquire.
Results
Across a matched four-week window, Meta (control) spent $18,896.70 to generate 3,691 leads at a $5.11 CPA with a 43.54% email open rate, while Performance Max (test) spent $4,660.75 for 541 leads at an $8.61 CPA with a 24.17% open rate. Meta significantly outperformed Performance Max on click-to-lead conversion rate (two-proportion z-test, p < 0.01), confirming the CPA gap reflects real efficiency differences rather than budget or volume. PMax's CPA runs 68% higher than Meta's, a $3.50 absolute difference. The bigger story is quality: Meta leads open follow-up emails at 43.54% versus 24.17% for PMax. Adjusting CPA by open rate as an engagement proxy, the effective cost per engaged lead is about $11.74 on Meta versus $35.62 on PMax.
Key Takeaways
Meta remains the primary platform for high-volume, low-cost lead acquisition. PMax delivered workable absolute CPAs but at a meaningful premium and with materially lower downstream engagement. We'd recommend using it as a supplemental channel where Meta scale or reach is constrained, not a co-equal lever. Future tests should balance spend and track lead-to-conversion, not just lead-to-open, to see whether the quality gap holds further down the funnel.
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Test Details
Vertical
Advertising
KPI
Cost Per Lead