Paid media and measurement · Large-scale randomized advertising experiment
Estimating the Value of Offsite Tracking Data to Advertisers: Evidence from Meta
Wernerfelt, N., Tuchman, A., Shapiro, B. T., & Moakler, R. (2025). Marketing Science, 44(2), 268–286.
Plain-English take
The median cost per additional customer was estimated at $38.16 at baseline and $49.93 under the median loss in effectiveness when offsite data could not be used, a 31% increase. For your marketing: This may be useful for thinking about privacy-related measurement loss and incrementality, especially for small advertisers.
How much weight to give this
4.0/5 Useful evidence with meaningful caveats
The 1–5 evidence-check score is a practical reading aid, not a formal peer review or a probability that a conclusion is true. It combines design strength (2 points), sample reporting (1), comparison/control clarity (1), and how much of the paper could be checked (1). Access affects how confidently this directory can assess a study, not the study's underlying quality. Blinding is reported separately because it is not relevant to every design.
Random assignment provides a strong comparison for effects in the tested setting.
A usable sample size is not stated in the profile's accessible source.
Randomized comparison; confirm the control condition and analysis in the paper.
This profile could be checked against an abstract or metadata, not the full paper.
Double-blind? Blinding is not reported in the source reviewed; that does not establish whether blinding was or was not used.
Research question
What the authors investigated
How much does offsite tracking data improve ad delivery effectiveness for advertisers?
Design
Randomized experiment across live campaigns, with deconvolution methods used to estimate distributions of campaign-level effects.
Sample and setting
More than 70,000 Facebook and Instagram advertiser experiments across over 160 countries.
Reported result
What the study found
The median cost per incremental customer was estimated at $38.16 at baseline and $49.93 under the median loss in effectiveness when offsite data could not be used, a 31% increase. The estimated loss was larger for small advertisers; purchase-optimized ads generated more long-term customers per dollar than click-optimized ads.
This is a paraphrase of the source. Check the original paper for definitions, estimates, statistical uncertainty and analysis details.
Scope and transfer
Limitations to keep in view
The experiment is partial-equilibrium and does not measure broader market adjustment or consumer privacy welfare. Offsite purchases and opted-out users are not fully observed, so some effects may be missed.
Possible founder application
Useful for thinking about privacy-related measurement loss and incrementality, especially for small advertisers. The Meta campaign economics and targeting system are platform-specific and should not be treated as a universal CAC benchmark.
Evidence access
Publisher abstract; full text may require access
INFORMS publisher abstract retrieved with Firecrawl; reported experiment scope, sample, results and limitations are summarized at abstract level.
If only an abstract or metadata was available, the profile is limited to claims supported there. A paper's paywall does not change its evidentiary status, but it limits what we can substantiate from accessible text.