Rosie O’Meara

Chief Executive Officer GroundTruth

Last Reviewed: September 29, 2026

Executive Summary

Rosie O’Meara is Chief Executive Officer of GroundTruth, the New York advertising platform that uses real-world location and behavioral signals to target campaigns and measure store visits. She took the role in April 2024 after five years as the company’s Chief Revenue Officer. In March 2026 she led GroundTruth into its acquisition by ZeroToOne.AI, a predictive behavioral AI company, and she has continued as CEO under the new owner. Before GroundTruth she founded and ran Zapp360, a mobile marketing platform for local media companies, until a4Media acquired it in 2018.

Career Highlights

• Chief Executive Officer of GroundTruth since April 2024, succeeding Steve McCarthy.
• Remained CEO after ZeroToOne.AI acquired GroundTruth in March 2026. GroundTruth then served more than 2,000 enterprise customers.
• As Chief Revenue Officer from 2019, led top-line growth and oversaw sales, and was involved in the Addy acquisition, performance CTV integration and the reseller marketplace.
• As CEO of Zapp360, built a profitable SaaS mobile marketing platform for local media companies, which a4Media acquired in 2018.
• 2022 Top Women In Media and AdTech honoree, and a board member of the DPAA and its women’s group WE.DOOH.

Professional Journey

O’Meara began in New York-based brand and agency sales teams at Verve Mobile and ITN Digital. She then led Zapp360 as chief executive and built it into a profitable software-as-a-service platform that local media companies used to sell and run mobile marketing. In 2018 a4Media acquired Zapp360, and she joined a4Media as Vice President of Customer Success & Mobile Initiatives.

She joined GroundTruth in 2019 as Chief Revenue Officer, responsible for top-line growth across all of its products and for the sales teams. The company lists several growth initiatives from that period that she worked on, including the acquisition of Addy, the integration of performance connected-TV advertising, and a marketplace for resellers. She was also executive sponsor of the company’s diversity, equity, inclusion and belonging programme and sat on the committee of Women@GroundTruth.

In April 2024 the board appointed her Chief Executive Officer. She succeeded Steve McCarthy, who stayed on as a director. Two years later, in March 2026, ZeroToOne.AI announced that it had acquired GroundTruth. The buyer is a predictive-AI company whose Large Behavioral Model was developed by researchers recruited from Carnegie Mellon University. The logic of the deal was to run ZeroToOne’s prediction engine over GroundTruth’s network of real-world signals and its customer base of more than 2,000 enterprises. “As one company, we can move beyond measuring behavior to predicting it,” she said at the time. GroundTruth’s leadership moved across with the business. By August 2026 GroundTruth was describing itself as “a ZeroToOne.AI company”, and its jointly built Dynamic Intent Prediction audiences had won a MarTech Breakthrough award. GroundTruth’s site continues to list her as its chief executive.

She is based in New York.

Education

No education record was found in the company or event biographies reviewed.