“It’s the fastest-growing part of our industry,” Mr. Emrich said.

Gimbal wants to use TrueX’s technology to, for instance, help marketers tell whether someone who browsed their products online is worth advertising to and whether any such ad drove results, like a store visit.

TrueX’s technology was attractive because of the firm’s relationship with TV app owners, Mr. Emrich said, but also because its system solicits information on what viewers are interested in—while also helping establish that they are real humans, not bots designed for ad fraud.

“Is this a real person because they are interacting with it?” Mr. Emrich said. “That’s a huge problem in the industry.”

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