# Brian Mandelbaum

> Brian Mandelbaum is the Chicago-based cofounder and CEO of Attain, which uses permissioned consumer purchase data for advertising audiences, insights and measurement. He previously founded video advertising company Clearstream TV, acquired by Engine Group in 2015, and worked in digital strategy at Saatchi & Saatchi and Cramer-Krasselt.

- **Role:** CEO and Cofounder at Attain
- **Organizations:** Attain, Clearstream TV, Saatchi & Saatchi, Cramer-Krasselt, Mayne Capital
- **Education:** Quinnipiac University - School of Business
- **Known for:** Founded Clearstream TV and led the business before its 2015 acquisition., Cofounded Attain and led its expansion into purchase-based advertising measurement., Attain raised a $25 million Series B in 2022.

## Career timeline

- **2008** — Joined Cramer-Krasselt as vice president and interactive group media director after serving as director of interactive at Saatchi & Saatchi/New York.
- **2011** — Founded Clearstream TV.
- **2014** — Clearstream introduced Play-In-View video advertising technology.
- **2015** — Clearstream TV was acquired by Engine Group.
- **2019** — Cofounded the company originally called Klover, now Attain, with CTO Dominic Bennett.
- **2022** — Parent company rebranded to Attain and announced a $25 million Series B led by Mercato Partners; the Klover app retained its name.
- **2023** — Attain announced partnerships with The Trade Desk and DoubleVerify; launched Frisbee.
- **2024** — Attain acquired Merryfield on September 24.
- **2026** — Announced Till 1.1, a consumer demand model built on purchase behavior.

## Achievements

- Founded Clearstream TV and led the business before its 2015 acquisition.
- Cofounded Attain and led its expansion into purchase-based advertising measurement.
- Attain raised a $25 million Series B in 2022.
- Reported nearly 70% company growth, more than 100% enterprise growth and profitable growth for 2025.

## Latest updates

- **2026-09** — Announced Till 1.1 in a LinkedIn post, describing simulations of consumer demand evaluated against actual purchases.
- **2025-12** — Reported nearly 70% company growth and more than 100% enterprise growth for 2025, alongside profitable growth.
- **2025-07** — Discussed Attain’s role in PMG’s Alli Marketplace and advertising accountability at Cannes Lions.
- **2025-04** — Explained purchase-based audiences and Attain’s Experian marketplace integration in an interview.

## Links

- LinkedIn: https://www.linkedin.com/in/brianmandelbaum/

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Profile page: https://yespress.io/brian-mandelbaum
Published by YesPress — https://yespress.io
Last updated: 2026-10-23