Best Buy partners with Magnite to scale programmatic advertising reach

Consumer electronics retailer Best Buy has selected Magnite as its exclusive supply-side platform and curation partner to expand programmatic access to its advertising inventory. The partnership, announced September 19, 2025, aims to grow Best Buy Ads' scale across onsite and offsite channels while providing agencies and buyers with programmatic access to the retailer's customer data and advertising opportunities.

Best Buy's media arm handles over two billion customer interactions annually across online, in-store, and in-home touchpoints. According to the announcement, these interactions come from nearly 80% of the US adult population, creating a substantial advertising footprint for brands seeking to reach electronics shoppers.

The partnership represents a significant development in the rapidly expanding retail media sector. Recent industry research shows retail media networks will exceed $300 billion by 2030, representing 20% of global advertising revenue, as retailers recognize the revenue potential of their customer data and digital properties.

Targeting high-intent shoppers with first-party data

Best Buy operates 600 stores across the United States and maintains relationships with over 600 brands through its media business. The retailer enriches its customer data with 15,000 unique attributes, enabling targeted campaigns across multiple channels. This data infrastructure supports Best Buy's ability to deliver precision advertising to consumers actively researching and purchasing electronics.

The Magnite partnership will open programmatic access to both owned and operated inventory as well as offsite placements. Previously, much of Best Buy's premium advertising inventory required direct sales relationships or specialized platforms. Now, agencies and demand-side platforms can access this inventory through standard programmatic channels.

According to the partnership announcement, Best Buy Ads can tie 93% of all transactions to customer IDs across in-store, app, and online purchases. This transaction transparency enables performance-oriented advertising that extends beyond traditional digital metrics to actual purchase behavior. The level of attribution capability distinguishes retail media from traditional publisher advertising, where purchase correlation remains challenging to establish.

Extending reach through Connected TV curation

The partnership will leverage Magnite SpringServe technology to enable programmatic access to Best Buy's curated inventory through deal IDs. This approach allows advertisers to reach Best Buy customers outside of Best Buy-owned properties while maintaining alignment with brand and shopper data.

Connected TV represents a key expansion area for the partnership. Industry data shows CTV's share of media budgets projected to double from 14% in 2023 to 28% in 2025, reflecting broader shifts toward streaming advertising investment. Best Buy's customer data can enhance CTV targeting by identifying viewers who have demonstrated electronics purchase intent.

The curation approach addresses fragmentation challenges that have hindered retail media growth. Brands working with four to six retail media networks doubled from 10% to 24% in 2025, signaling diversification strategies among advertisers. Programmatic access through established platforms like Magnite reduces operational complexity for agencies managing multiple retail partnerships.

Deal ID structures enable advertisers to access specific audience segments or inventory types while maintaining campaign control. Rather than open marketplace bidding, curated deals provide guaranteed access to defined inventory pools with predetermined pricing or bidding parameters.

Performance measurement and closed-loop attribution

Best Buy's transaction data capabilities enable closed-loop measurement that connects advertising exposure to actual purchases. The retailer can track customer journeys from initial ad exposure through final transaction across online and offline channels. This measurement approach provides advertisers with concrete return on investment data rather than proxy metrics like click-through rates or view-through conversions.

The partnership with Magnite will integrate these measurement capabilities with programmatic campaign management. Advertisers can optimize campaigns based on actual sales performance while maintaining the automation and scale advantages of programmatic buying. This combination addresses longstanding challenges in retail media where premium data often required manual campaign management.

Magnite's extensive Connected TV and omnichannel supply will create opportunities for cross-channel campaigns that follow customers from consideration through purchase. According to industry analysis, Magnite maintains 99% of CTV supply coverage and 96% of overall omnichannel supply coverage, providing broad reach for Best Buy audience extensions.

Industry context and competitive landscape

The Best Buy-Magnite partnership reflects broader retail media industry maturation. European retail media spending grew 22.1% in 2024 compared to 6.1% growth for the broader advertising market, demonstrating retail media's transition from experimental category to strategic advertising infrastructure.

Programmatic adoption in retail media has accelerated across both offsite and onsite inventory. While offsite retail media has operated programmatically for years, onsite sponsored products are increasingly moving toward real-time bidding mechanisms. The Pentaleap-Teads partnership delivered the first RTB solution for onsite sponsored products across multiple retail networks in July 2025.

Major retailers are establishing their advertising businesses as independent revenue streams. Criteo became Google's first onsite retail media partner through Search Ads 360 integration, while auction-based display advertising systems provide programmatic flexibility previously unavailable in retail environments.

Best Buy's partnership with Magnite positions the retailer within this competitive landscape while leveraging Magnite's technical infrastructure and buyer relationships. Rather than building proprietary programmatic capabilities, Best Buy can access established demand sources through Magnite's platform while maintaining control over inventory and pricing.

The electronics retail category provides unique advantages for programmatic advertising. Consumer electronics purchases often involve significant research phases where targeted advertising can influence consideration and final purchase decisions. Best Buy's combination of online research tools, in-store experience, and installation services creates multiple touchpoints where advertising can drive customer engagement.

Technical implementation and activation

Campaign activation with Best Buy inventory requires coordination through Magnite account managers or direct contact with the platform. The programmatic access will complement Best Buy's existing direct sales relationships rather than replacing them entirely. Enterprise clients may continue direct partnerships while agencies and smaller advertisers can access inventory through programmatic channels.

The SpringServe integration will enable real-time bidding on Best Buy's offsite inventory while maintaining brand safety and audience quality controls. Advertisers can apply their own first-party data for additional targeting while benefiting from Best Buy's customer insights and transaction data.

Cross-device tracking and measurement will connect advertising exposure across desktop, mobile, and Connected TV environments with in-store and online purchase behavior. This attribution approach supports comprehensive campaign optimization that accounts for the complex customer journeys common in electronics purchases.

The partnership timeline and technical implementation details were not disclosed in the September 19 announcement. Campaign activation will likely begin with beta testing among select agency and advertiser partners before broader availability.

Timeline

• September 19, 2025: Best Buy Ads announces Magnite as exclusive SSP and curation partner for programmatic expansion
• September 10, 2025: Criteo becomes first onsite retail media partner for Google Search Ads 360
• September 4, 2025: Omdia research projects retail media to capture 20% of global ad revenue by 2030
• August 21, 2025: Magnite becomes first sell-side partner for Acxiom data activation
• July 30, 2025: IAB Europe survey reveals growing retail media partnerships as brands diversify across networks
• July 24, 2025: Pentaleap and Teads announce industry-first RTB integration for retail media sponsored products
• June 17, 2025: Criteo launches auction-based display technology for retail media flexibility
• May 7, 2025: Magnite reports strong Q1 2025 results with 15% CTV growth
• April 23, 2025: Magnite unveils next generation SpringServe platform combining ad server with SSP capabilities

Summary

Who: Best Buy Ads, the consumer electronics retailer's media division, and Magnite, the largest independent sell-side advertising platform

What: Exclusive partnership designating Magnite as Best Buy's supply-side platform and curation partner to expand programmatic access to advertising inventory across onsite and offsite channels

When: Announced September 19, 2025, with campaign activation timeline to be determined

Where: United States market initially, focusing on Best Buy's network of 600+ stores and digital properties reaching nearly 80% of US adult population

Why: To scale advertising opportunities for brands seeking to reach high-intent electronics shoppers while providing agencies and buyers with programmatic access to Best Buy's customer data and inventory through established platforms rather than direct sales relationships