Mario Diez
Mario Diez is the CEO of Peer39, a contextual intelligence and brand safety company that helps advertisers reach audiences through semantic page analysis without relying on cookies or personal data. Under his leadership, Peer39 has positioned itself as a key player in the industry's shift toward cookieless targeting, offering solutions for brand suitability, contextual targeting, and pre-bid inventory quality across programmatic channels. Diez has a background in digital media and advertising technology, with experience spanning publisher-side and platform-side roles. He has been a vocal advocate for contextual and semantic approaches to advertising as the industry navigates the deprecation of third-party cookies and evolving privacy regulations. At Peer39, he has overseen the company's growth and product expansion, including its integration with major DSPs and SSPs, and has represented the company in industry conversations around brand safety standards and the future of programmatic targeting.
Last updated Oct 23, 2026 by ATDb automated enrichment · Connections updated Oct 26, 2026
AI-drafted from public sources1 source cited
- Years in industry
- 15 years
Bio
Mario Diez is the CEO of Peer39, a contextual intelligence and brand safety company that helps advertisers reach audiences through semantic page analysis without relying on cookies or personal data. Under his leadership, Peer39 has positioned itself as a key player in the industry's shift toward cookieless targeting, offering solutions for brand suitability, contextual targeting, and pre-bid inventory quality across programmatic channels. Diez has a background in digital media and advertising technology, with experience spanning publisher-side and platform-side roles. He has been a vocal advocate for contextual and semantic approaches to advertising as the industry navigates the deprecation of third-party cookies and evolving privacy regulations. At Peer39, he has overseen the company's growth and product expansion, including its integration with major DSPs and SSPs, and has represented the company in industry conversations around brand safety standards and the future of programmatic targeting.
Expertise & education
Expertise
Speaking topics
Recognition
Notable achievements
- Led Peer39's expansion as a leading contextual and semantic targeting platform during the industry's transition away from third-party cookies
- Grew Peer39's integrations across major DSPs and SSPs to scale cookieless targeting solutions