We removed a prelander from a native lead-gen campaign. CPC rose 15%. CPL jumped 234%

Hi Native Ads Gurus! Here I come with a fresh paid experiment from the beggining of this October. We ran an experiment with native advertising traffic from our local native ad network for a Spanish nonprofit. The goal was to generate qualified leads, not just clicks or email signups.

Each conversion required five fields: first name, last name, email, phone number, and preferred contact date.

Instead of sending every click directly to the advertiser, we introduced a lightweight PreContent (you may call it prelanding or prelander) layer : a short editorial experience where visitors could understand the topic and voluntarily decide whether to continue.

Here's what happened. We wrecked everything when we were obtaining 5 fields-leads well under 1 euro CPL. (on purpose...).

The funnel with PreContent:

1,521 arrivals

906 stayed at least 8 seconds (59.6%)

585 voluntarily continued (38.5%)

81 completed leads

13.8% conversion from continuation to lead

Meanwhile, direct traffic generated 70 leads from 1,351 clicks (5.2%).

These aren't directly comparable conversion rates. The PreContent visitors had already self-selected before reaching the advertiser's form.

Then we switched PreContent OFF.

Using the PreContent period as index 100:

Metric ON OFF

CPC 100 115

Conversion rate 100 34

CPL 100 334

CPC increased just 15%, but CPL increased 234%.

In one reporting period, we spent €122.90 and generated 139 advertiser-confirmed leads: €0.88 CPL. During some optimized days, CPL dropped below €0.50.

And these were five-field leads, not simple clicks or newsletter subscriptions.

But here's what I found even more interesting.

PreContent wasn't just filtering visitors.

It was showing us which publisher/placement combinations and visitor journeys produced better downstream engagement.

We started using those signals to improve media buying decisions.

The process became:

Native traffic → PreContent → Behavioral signals → Better buying decisions → Lead

Essentially, the intermediate page became a source of optimization data, not just another step in the funnel.

Now, the caveats.

This wasn't a randomized A/B test. Inventory changes, day-of-week effects and ongoing optimization could have influenced the results.

And time on page isn't necessarily a reliable indicator of purchase or conversion intent. We care much more about whether visitors actually progress toward the final conversion.

Our next step is to reactivate the same PreContent and see whether performance recovers, followed ideally by a simultaneous A/B test.

What I'm curious about:

Are we sometimes optimizing native campaigns for the wrong click?

Have you seen CPL improve after deliberately adding friction to the conversion journey?

And are you using post-click behavioral signals to optimize placement-level buying, or mainly relying on CTR, CPC and final conversions?