Platform · Rapid Message Testing

Know which message wins
before you buy ads.

Unlike traditional surveys or A/B tests, our Randomized Controlled Trials tell you what changes minds, not just what people already believe. Results in as little as 24 hours.

app.growprogress.ai
Message Performance
Corporate
lobbyists
Health care
investment
Medicaid
cuts
Corporate
greed
Vote choice
Baseline: 35%
+3
+2
+3
+2
Priority
Baseline: 58%
+0
−1
+1
−4
Handling taxes
Baseline: 26%
+6
+5
+6
+5
Bigger problem
Baseline: 36%
+5
+8
+2
+2
(−) Backlash
(−) Directional
No measurable effect
(+) Directional
(+) Persuasive
Subgroups
Age Race Education Household Income Parental Status Party ID Urbanicity 2024 Presidential Vote And more…
Message Effect
(−) Backlash
(−) Directional
No Measurable Effect
(+) Directional
(+) Persuasive

Trusted by leading campaigns, nonprofits, labor unions, and advocacy organizations

SEIU NEA Galvanize Action Progress Now Equis Research Feeding America Forward Majority
Brennan Center for Justice A Better Wisconsin Together World Central Kitchen Conservation Law Foundation ACLU Democratic Party AFL-CIO
Earthjustice EDF Refugees International Orchestra GSG charity: water
What It Is

A randomized controlled trial, built for persuasion.

Rapid Message Testing uses the same gold-standard methodology as clinical drug trials and academic social science, adapted for the speed of modern communications.

Respondents are randomly assigned to comparable groups — statistically identical going in. Each test group sees one piece of content: a video ad, a piece of mail, a social post.

The control group sees neutral, unrelated content instead. That's the only difference between them.

Then we ask what they believe and how they intend to act. Any difference in their answers is the causal effect of the content — not correlation, not self-report.

Other methods ask people to predict what will persuade them. They can't. RMT doesn't ask. It measures. That's the line between knowing a message works and guessing. You're not limited to one. Run several pieces of content side by side and you don't just learn whether something moves people, you learn which moves them most, measured against the same control group, on the same scale, at the same time.

Nationally Representative Respondents
Randomly Assigned
Sees no message, establishes baseline
Control Group
Sees your message, effect measured here
Test Group
Opinion Survey
38%
support
Opinion Survey
56%
support
Grow Progress Lift
Δ = 56% 38% = +18 pts
Causal lift, not correlation
What You Can Test

Works for every format
your org actually uses.

If your campaign or organization uses it to persuade people, you can test it.

TV ads
Digital ads
Mail
Email
Phone
Text
Canvassing scripts
Social content
Why It Works

Most research tells you what people think.
Rapid Message Tests tell you what changes their minds.

Causal
Causal, not correlational
RCTs measure what changes minds, not just what people already believe. When random assignment creates the groups, the only thing that can explain a difference in outcomes is the message itself.
Speed
Speed that matches your timeline
24-hour turnaround means you can test, learn, and adjust mid-campaign. Not six weeks later when the window has closed. Test before your next mail drop. Test before you finalize your ad buy.
Precision
Subgroup precision
See results broken down by party, demographics, and geography, not just topline. The message that moves Democrats may land differently with independents.
Get Started

Ready to test your messages?

Talk to our team. We'll walk you through a real RMT example and show exactly how message testing fits your timeline and budget.