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Stephen Chester

Standards Setter

Stephen Chester is a senior figure in the UK advertising and media industry, serving as Director of Media at ISBA, the Incorporated Society of British Advertisers. In this role he leads ISBA's work on media transparency, programmatic supply chain integrity, media measurement and advertiser interests across broadcast, digital and out-of-home channels. Chester has been closely associated with ISBA's landmark Programmatic Supply Chain Transparency Study, conducted in partnership with PwC and the AOP, which exposed significant levels of 'unknown delta' — unattributed costs — within the programmatic advertising ecosystem. This work has made him a prominent voice on media accountability and the need for greater clarity in how advertiser budgets flow through digital media. He regularly engages with industry bodies, regulators and media owners on behalf of ISBA's membership of major UK and multinational advertisers, contributing to debates around media agency contracts, audience measurement reform and brand safety.

Last updated Oct 23, 2026 by ATDb automated enrichment · Connections updated Oct 26, 2026

Role
Director of Media
Company
ISBA
Based
London, United Kingdom
Connections
1

AI-drafted from public sources1 source cited

Years in industry
15 years

Bio

Stephen Chester is a senior figure in the UK advertising and media industry, serving as Director of Media at ISBA, the Incorporated Society of British Advertisers. In this role he leads ISBA's work on media transparency, programmatic supply chain integrity, media measurement and advertiser interests across broadcast, digital and out-of-home channels. Chester has been closely associated with ISBA's landmark Programmatic Supply Chain Transparency Study, conducted in partnership with PwC and the AOP, which exposed significant levels of 'unknown delta' — unattributed costs — within the programmatic advertising ecosystem. This work has made him a prominent voice on media accountability and the need for greater clarity in how advertiser budgets flow through digital media. He regularly engages with industry bodies, regulators and media owners on behalf of ISBA's membership of major UK and multinational advertisers, contributing to debates around media agency contracts, audience measurement reform and brand safety.

Expertise & education

Expertise

Programmatic AdvertisingMedia TransparencySupply Chain AccountabilityMedia MeasurementBrand SafetyMedia Agency RelationshipsDigital Media PolicyAdvertiser Advocacy

Speaking topics

Programmatic supply chain transparencyMedia accountability and measurementAdvertiser interests in digital mediaBrand safety

Recognition

Notable achievements

  • Led ISBA's Programmatic Supply Chain Transparency Study with PwC and AOP, revealing significant unattributed costs in the UK programmatic ecosystem
  • Represents major UK advertisers in industry-wide debates on media measurement reform and agency transparency
Connection details