# Epsilon Data Management, LLC
> Epsilon · Irving, Texas
- Profile type: Company
- Profile status: baseline
- Last updated: 2026-05-03T00:00:00.000Z
- Canonical URL: https://thestateofstreaming.com/companies/epsilon/
- Also known as: Epsilon, Epsilon Interactive, Conversant (Epsilon)
## Summary
Epsilon is the people-based identity, data, and martech spine of Publicis Groupe. Acquired from Alliance Data Systems in July 2019 for $4.4 billion, it powers PeopleCloud, the CORE ID identity graph, and Discovery — the data layer Publicis pitches as the post-cookie alternative to walled-garden and cookie-based addressability.

## Company facts

- Founded: 1969
- Headquarters: Irving, Texas
- Domain: epsilon.com
- CEO: sean reardon (https://thestateofstreaming.com/people/sean-reardon/)


## Key facts

- Publicis Groupe completed its acquisition of Epsilon from Alliance Data Systems on July 2, 2019, for a $4.4 billion cash consideration ($3.95 billion net of acquisition-related tax step-up), implying an 8.2x Adjusted EBITDA multiple. — Epsilon press release: https://www.epsilon.com/us/about-us/pressroom/publicis-groupe-finalizes-the-acquisition-of-epsilon
- At close, Epsilon brought roughly 9,000 staff to Publicis, including approximately 3,700 data scientists, plus loyalty software serving 600 million accounts. — Bloomberg: https://www.bloomberg.com/news/articles/2019-04-14/publicis-to-buy-alliance-data-s-epsilon-unit-for-4-4-billion
- Sean Reardon, formerly Global CEO of MiQ and CEO of Dentsu Media Americas, was named CEO of Epsilon on October 23, 2025 — the first standing CEO since Bryan Kennedy's 2021 retirement. — Epsilon press release: https://www.epsilon.com/us/about-us/pressroom/sean-reardon-named-ceo-of-epsilon
- Epsilon was named a Leader in the 2025 IDC MarketScape for Worldwide Connected TV Advertising Platforms, with the assessment crediting CORE ID for consolidating disparate audiences into a single deduplicated ID across CTV households. — Epsilon press release / IDC MarketScape: https://www.epsilon.com/us/about-us/pressroom/epsilon-named-a-leader-in-2025-idc-marketscape-for-ctv
- Epsilon partnered with TransUnion in June 2025 to connect its 250-million-consumer database to TransUnion's 80-million-household identity graph, expanding CTV targeting and measurement reach. — Marketing Dive: https://www.marketingdive.com/news/epsilon-transunion-ispottv-data-ctv-targeting-measurem/625299/


## Related

- publicis groupe (parent) — https://thestateofstreaming.com/companies/publicis-groupe/
- acxiom (competitor) — https://thestateofstreaming.com/companies/acxiom/
- liveramp (competitor) — https://thestateofstreaming.com/companies/liveramp/
- lotame (competitor) — https://thestateofstreaming.com/companies/lotame/
- epsilon peoplecloud (product) — https://thestateofstreaming.com/products/epsilon-peoplecloud/
- core id (product) — https://thestateofstreaming.com/products/core-id/
- epsilon discovery (product) — https://thestateofstreaming.com/products/epsilon-discovery/
- identity resolution (category) — https://thestateofstreaming.com/tech/identity-resolution/
- data clean rooms (category) — https://thestateofstreaming.com/tech/data-clean-rooms/
- sean reardon (CEO) — https://thestateofstreaming.com/people/sean-reardon/
- john giuliani (executive-chairman) — https://thestateofstreaming.com/people/john-giuliani/


## External coverage

- 2019-07-02 — Epsilon: Publicis Groupe Finalizes the Acquisition of Epsilon (https://www.epsilon.com/us/about-us/pressroom/publicis-groupe-finalizes-the-acquisition-of-epsilon)
- 2020-11-09 — Publicis Groupe: Epsilon Positioned at the Center of Publicis Groupe Growth Strategy (https://www.publicisgroupe.com/en/news/press-releases/Epsilon-Positioned-at-the-Center-of-Publicis-Groupe-Growth-Strategy)
- 2025-10-23 — Epsilon: Sean Reardon Named CEO of Epsilon (https://www.epsilon.com/us/about-us/pressroom/sean-reardon-named-ceo-of-epsilon)
- 2025-10-23 — Ad Age: Publicis hires an Epsilon CEO as data becomes core to its growth strategy (https://adage.com/agencies/aa-epsilon-new-ceo-sean-reardon)
- 2019-04-14 — CNBC: Publicis announces $4.4 billion deal to acquire data marketing company Epsilon (https://www.cnbc.com/2019/04/14/publicis-to-buy-epsilon-for-4point4-billion.html)
- 2025-06-01 — Epsilon: Epsilon Named a Leader in 2025 IDC MarketScape for CTV Advertising Platforms (https://www.epsilon.com/us/about-us/pressroom/epsilon-named-a-leader-in-2025-idc-marketscape-for-ctv)

## Profile
Epsilon is the data and identity engine inside Publicis Groupe, and the only piece of the holdco's stack that competes head-to-head with the independent identity infrastructure of LiveRamp, Acxiom (now part of IPG), and the walled gardens. Publicis paid $4.4 billion for it in 2019 — the largest single bet any agency holding company has made on owning the addressability layer rather than renting it — and has since positioned PeopleCloud, CORE ID, and Discovery as the products clients touch when Publicis sells "connected media" to them.

The company sat without a standing CEO from Bryan Kennedy's 2021 retirement until October 2025, when Publicis named Sean Reardon — a Publicis alum who returned via MiQ and Dentsu — to the role. Reardon's appointment, paired with Epsilon's 2025 IDC MarketScape Leader designation for CTV advertising platforms and a TransUnion identity-graph partnership the same month, marks the start of a more aggressive standalone posture for the unit inside the broader Publicis Connected Media structure.

## Tags

- identity
- publicis
- addressable
- first-party-data
- ctv-identity
- holding-companies

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