The CS Method™
How to Measure CTV Incrementality
Hold back a matched group of households that can’t see your ads, run the campaign to everyone else, then compare purchases, leads or sign-ups between the two groups in your own data. The gap is what CTV caused. We build this test into every campaign with The CS Method™.
- Holdout in every campaign
- Read in your own data
The gap is what CTV caused. Checked against the brand’s own orders with The CS Method™.
Brands our team has made work for: production, creative and campaigns.
What is CTV incrementality?
The extra sales your CTV ads caused: the ones that wouldn’t have happened without them.
Only a control group can separate the two.
Attribution
Shows which purchases happened near an ad.
Incrementality
Shows which ones the ad caused.
How do you run a CTV incrementality test?
Agree the KPI in writing
The number you’re held to, before a dollar runs.
Hold out matched households
A group that looks like your audience and never sees the ads.
Run long enough to read it
Long enough to cover how long your buyers take to decide.
Read it in your own data
Orders, CRM or policy system, not only the platform’s report.
Price the lift
Turn the gap into an incremental cost per customer.
What did a CS & Co. incrementality test show?
A May 2026 lift test run by the CTV platform showed 41.4% more purchases among households that saw the ads than among matched households that didn’t. We didn’t stop at the platform’s report: The CS Method™ checked its numbers against the brand’s own orders.
The numbers behind the caffeine
Each platform counts purchases by its own rules; the CTV figure uses a 7-day window. In July, CTV ran on a smaller budget weighted to warm audiences. Client name withheld. Read the case study →
Why isn’t platform attribution enough?
The seller shouldn’t be the only judge.
The platform that sold the ads also reports on them. Its lift test is a start; check it against your own orders.
Short windows hide the delay.
In the case study the typical buyer purchased 8 days after the ad, and a third after two weeks.
Correlation isn’t cause.
People who would have bought anyway see ads too. A holdout removes them.
Incrementality vs. attribution vs. media mix modeling
We use all three; the incrementality test is the referee.
Incrementality test
What did CTV cause?
Best for: proving a campaign worked
Attribution
Which purchases happened near an ad?
Best for: day-to-day optimization
Media mix modeling
How do channels add up over time?
Best for: budget planning across channels
Straight answers
Frequently asked questions
What is a CTV incrementality test?
A test that holds back a matched group of households that never see your ads, runs the campaign to everyone else, and compares purchases, leads or sign-ups between the two groups in your own data. The difference is what CTV caused.
How long should a CTV incrementality test run?
Long enough to cover how long your buyers take to decide. In CS & Co.'s health & wellness case study the typical buyer purchased 8 days after seeing an ad, and a third after two weeks, so a test read after a few days would miss most of the effect.
What budget does an incrementality test need?
Enough to run long enough, at a sensible frequency, to read a difference between the two groups. CS & Co. sizes it on the fit call for your purchase volume.
One way to start
What would CTV cause for your brand?
If CTV is right for your business, we’ll show you the math. If it’s not, we’ll tell you that too, before you spend a dollar.
Find out if CTV is a fitStarts with a 15-minute fit-and-scope call with a senior operator, not an SDR.