Discover how SKIMS leveraged TikTok marketing measurement with LiftLab experiments to triple spend efficiency and skyrocket online sales.
SKIMS validated TikTok as a profitable channel through a six-week geo-based experiment that withheld ads in control regions while running them in matched test regions. The test measured incremental, not self-reported, revenue and found daily revenue could rise 2.9% and profit 1.7%, with room to increase spend 3.4x before returns started to diminish. Full results are detailed below.
Business Challenge
SKIMS’ marketing team believed TikTok could be a valuable channel, given its reach and ability to target their specific demographic, but a hunch isn’t a budget justification. TikTok’s own in-platform analytics are self-reported, making it hard to know whether the platform’s numbers reflected real incremental revenue or simply captured customers who would have converted anyway. Before committing meaningfully more budget, SKIMS needed an independent, credible way to test whether TikTok’s promise was actually paying off.
Objectives
Confirm whether TikTok was genuinely driving incremental revenue, not just capturing existing demand
Test the hypothesis with a credible, independent method rather than relying on TikTok’s self-reported numbers
Determine how much room there was to safely increase spend without hitting diminishing returns
How LiftLab’s Agile MMM Platform Approached It
LiftLab ran a geo-based incrementality test to answer the question directly:
Matched test and control regions: The country was split into statistically matched markets, with TikTok ads run in treated regions and withheld in control regions
A six-week experiment: Experiments were run long enough to capture a reliable read on TikTok’s actual incremental impact, independent of TikTok’s own reporting
Incremental ROAS (iROAS) pinpointed for TikTok: Incrementality testing showed the true return TikTok generated, with 95% confidence in the result
Fed into the Agile Marketing Mix model: Results from the experiments now feed into the model weekly, letting SKIMS monitor TikTok alongside every other channel going forward
The full detail behind the approach deployed by LiftLab, how the test and control regions were matched, and how the diminishing returns curve was built, is covered in the downloadable case study at the bottom of this page.
Results & Business Impact
Daily revenue rose 2.9% and profit rose 1.7%, confirming TikTok was driving real, incremental growth rather than just capturing existing demand
LiftLab pinpointed incremental ROAS for TikTok specifically, with 95% confidence in the result
The lift curve showed SKIMS was nowhere near maximum profit, with room for marketing spend optimization to increase daily spend 3.4x before returns started to diminish
SKIMS’ guess about TikTok was validated independently, giving the team a credible basis to commit meaningfully more budget
What started as a hunch about TikTok’s potential resulted in a decision SKIMS could defend with data. SKIMS now has a repeatable framework for evaluating new channels before scaling spend, rather than relying on hunches or platform-reported numbers alone.
Key Takeaways
A channel hunch is worth testing before it’s worth funding. Geo-experiments turn intuition into evidence you can defend to leadership.
Self-reported platform analytics and true incremental impact are two different numbers. Independent measurement is what tells you which one you’re actually looking at.
Finding the point of diminishing returns is as valuable as finding what’s working. It tells you exactly how far you can safely go.
A one-time test only has value if it becomes an ongoing signal. Feeding results back into a live model keeps a channel’s performance current, not frozen at the moment of the experiment.
Want a detailed look at how LiftLab ran SKIMS’ TikTok geo-experiment, from test-and-control design to the resulting spend recommendation?
TikTok Incrementality Testing & Ad Effectiveness Measurement
What results did SKIMS achieve with LiftLab?
SKIMS validated TikTok as a profitable channel through a geo-based experiment, seeing daily revenue rise 2.9% and contributing profit rise 1.7%. LiftLab pinpointed the incremental ROAS for TikTok with 95% confidence, and the resulting lift curve showed SKIMS had room to increase daily spend 3.4x before hitting <a href=”https://liftlab.com/solutions/diminishing-returns-marginal-roi/”>diminishing returns.</a>
What marketing challenge was SKIMS facing?
SKIMS’ team believed TikTok could be a valuable channel based on its reach and audience targeting, but needed a credible, independent way to confirm that before committing meaningfully more budget. TikTok’s own analytics are self-reported, making it difficult to know whether the platform’s numbers reflected real incremental revenue or simply captured customers who would have converted regardless.
What is TikTok incrementality testing and how does it work?
TikTok incrementality testing measures whether TikTok ads actually cause additional revenue, rather than relying on the platform’s own reported numbers. In SKIMS’ case, this meant splitting the country into matched test and control regions, running TikTok ads in treated regions while withholding them in control regions for six weeks, then comparing the difference in revenue between the two groups.
What is incremental ROAS (iROAS) and why does it matter for TikTok advertising effectiveness?
Incremental ROAS isolates the return generated specifically by TikTok ad spend, separate from revenue that would have happened without any advertising at all. This distinction matters for TikTok advertising effectiveness because standard, platform-reported metrics can overstate a channel’s impact by including conversions that weren’t actually caused by the ads, making iROAS a more reliable basis for a spend decision.
Can LiftLab help my brand measure TikTok’s true impact on revenue?
Yes. LiftLab’s Agile MMM Platform is built to independently validate whether channels like TikTok are driving real, incremental growth rather than capturing demand that already existed. If your team has a channel hypothesis to test, or needs a credible, third-party read on TikTok ad measurement before committing more budget, request a demo to see how the experiment works.
