A strategy validation methodology developed by Spark No. 9.
Most companies are good at building products. The harder problem is knowing whether a product will land before you launch it. To combat this, companies run surveys, commission focus groups, and increasingly turn to AI-generated personas to get some signal before they go to market. The problem is that all of those methods produce the same kind of opinion-based data based on what people say they'll do.This is the Say Vs. Do Gap: the distance between what consumers say they'll do in research settings and what they actually do when it's time to make a real decision. Say data has never been a reliable predictor of do data. Spark No. 9 developed heat testing, research grounded in observed behavior rather than stated preferences, to bridge that gap and produce decision-grade evidence.
Most market research methods share a fundamental flaw: they ask people to predict their own behavior. Surveys, focus groups, and AI-generated personas all generate say data — responses shaped by social pressure, faulty self-knowledge, and the artificial context of being asked.The Say Vs. Do Gap is the systematic difference between what people say they'll do and what they actually do when encountering a real message in the real world, with no moderator, no prompt, and real stakes. It is the reason validated products fail at launch and why promising survey results so often fail to translate into sales.Heat testing is designed to bridge this gap by generating do data instead.
Heat testing is a market research and product validation methodology developed by Spark No. 9 and published in Harvard Business Review. It generates behavioral data by putting real messages in front of real audiences in the real world and measuring what they actually do. The result is a data-driven picture of where your market actually is — which is often a different place than where you assumed it would be. For a new launch, that means knowing which audience and message combination gives you the strongest foundation before you commit. For repositioning, it means finding new demand without risking the customer base you've already built.
Heat testing runs paid social ads to your target audiences across major platforms. Ad creative is designed to reflect specific positioning concepts, not just general brand awareness. Every audience-and-message pair receives the same budget, creating a true apples-to-apples comparison. The test doesn't require a large spend, only enough to reach statistical significance. What comes back is decision-grade evidence — real potential customers making real choices.
A heat test is designed to answer the questions that opinion-based research tends to get wrong. Who is your real audience, not just your assumed one? What specific message or framing drives real behavior rather than stated preference? Across all the audience and messaging combinations you test, where is demand strongest?
The resulting heat map makes patterns visible quickly. Certain combinations of audience and message generate strong response, while others generate almost none. The combinations with the highest activity tell you not just that demand exists, but where it exists and what positioning unlocked it. This specificity makes heat testing actionable in a way that traditional validation methods are not.
The methodology is not tied to any single stage of the product lifecycle. Companies use it before a launch, after a launch, and anywhere in between when something isn't working and they're not sure why.
Spark No. 9 introduced heat testing 17 years ago. In December 2022, it was presented to a global business audience through a feature in Harvard Business Review, recognized as a substantive alternative to the market research approaches most companies default to, and widely shared among product and marketing leaders navigating high-stakes launch decisions. The approach has since been applied across consumer, B2B, and enterprise product launches worldwide.
"To test new products, most companies rely on creating minimum viable products and testing customer feedback, or conducting focus groups or marketing surveys. There's another method companies should try: heat testing."
— Harvard Business Review, December 2022