Case Study
Channel Overlap & Programmatic Lift
Programmatic Ads Increase Organic Purchase Conversion Rate
Objective:
To determine to what extent exposure to programmatic advertising improves the conversion rate of users arriving via external sources, such as organic search traffic.
Background
We analyzed over 90,000 Organic user sessions for a client to compare conversion behavior between users who did not receive programmatic ad exposure (Control) and those who did (Test Groups). Test groups were segmented by ad format: display/banner, native, and video.
The particular conversion being measured here is a new purchase from Organic channel traffic. Repeat purchasers are not included as it would heavily bias the results.
Methodology
A two-proportion z-test was conducted to compare the conversion rate of each test segment to the control group. This statistical test measures whether the observed differences are significant or likely due to chance.
- Control Group (No Ad Exposure)
- Population: 75,681
- Conversion Rate: 0.728%
- Test Groups (Received Ads)
- Formats: Display, Native, Video
- Conversion Rates: 1.84% to 2.64%
All comparisons resulted statistically significant differences above a 95% Confidence Interval. This means we have sufficiently strong data to indicate if this experiment is repeated, we would expect to continue to see very similar performance characteristics.
Findings
Summary of Organic Conversion Lift
Our analysis revealed consistent and statistically significant increases in conversion rates among all user segments that received programmatic ad exposure compared to the control group. The performance lift was evident across all tested ad format —display/banner, native, and video—indicating that programmatic ads play a critical role in improving user engagement and driving downstream conversions.
Control Group Baseline
- Conversion Rate: 0.728%
- Population Size: 75,681
- These users interacted with the brand via external sources (e.g. organic search or referrals) without any programmatic ad exposure.
This group served as our benchmark for measuring the effect of ad exposure. Any improvement observed in the test groups could be attributed to the presence of programmatic advertising.
Conversion Lift Data Table
Every test segment that received programmatic ad exposure showed a significantly higher conversion rate compared to the control group:
|
Segment |
Population |
Conversions |
Conv Rate |
Lift vs Control |
|
Banner Overlap |
3,510 |
75 |
2.137% |
+193% |
|
Native Overlap |
3,532 |
65 |
1.840% |
+153% |
|
Native Video Overlap |
1,706 |
36 |
2.110% |
+190% |
|
Video Ad Overlap |
530 |
14 |
2.642% |
+263% |
All sets individually reached data significance at 95% confidence interval.
Key Takeaways
- Massive Lift in Conversions:
All test segments outperformed the control group by a wide margin. In fact, users who received video ads converted at more than 3.6x the rate of users who saw no ads. - Consistent Significance Despite Varying Sample Sizes:
Even the smallest segment (Video Ad Overlap, n=530) achieved a statistically significant result due to the magnitude of improvement in performance. - Display and Video Ads Are Especially Effective:
Display ads alone drove a +193% lift. Video ads saw the strongest relative lift (+263%), suggesting deeper engagement or stronger brand recall from video formats.
Interpretation
Exposure to programmatic ads doesn’t just drive direct conversions—it amplifies the performance of other traffic channels, such as organic search or referral visits. This overlap results in a multi-channel uplift effect, where paid impressions increase the likelihood of converting through unpaid channels.
Why This Matters for Your Business
- Statistically Proven: The results are not anecdotal—our tests meet the rigor of formal statistical validation.
- Consistent Lift: Every ad format we measure resulted in improved performance.
- Cross-Channel Value: Even if conversions appear to happen via organic search or another source, programmatic ads still deserve credit for influencing that outcome. While organic search may reap the reward of last-interaction conversion credit (GA4 will give all the credit to Organic Search), sufficient modeling weight needs to be granted to Programmatic which may have originated the user’s journey.
- Levy Online has an expansive toolkit of technology that can directly measure the impact of our programmatic advertising on other channels, including the measurement of programmatic influence on Organic Search behavior.
Get more qualified leads with smarter marketing.
Conclusion
If you’re investing in growth, programmatic advertising is a powerful amplifier. Levy Online staff are expert practitioners of Programmatic Advertising The data shows it works across formats and even at small scales. These results validate programmatic as a high-impact investment-not just for direct ROI, but for unlocking hidden value across your entire marketing mix.