Walmart vs. Target vs. Costco: The $100 Billion Retail Media War

The U.S. retail media market is evolving into one of the most lucrative arms races in consumer tech. With ad spending on retail media set to double to $100 billion by 2028, players like Walmart (NYSE:WMT), Target (NYSE:TGT), and Costco (NASDAQ:COST) are accelerating efforts to transform their e-commerce platforms into profit engines.

This isn't just an ad play—it's about reshaping business models.

Walmart: The E-Commerce Engine With Room to Run

According to analysts at Bernstein, Walmart has the clearest path to retail media scale. While it's unlikely to match Amazon's dominance, its U.S. e-commerce GMV is projected to double from $100 billion to $200 billion by FY2030, largely driven by third-party (3P) marketplace sellers.

Walmart's first-party (1P) vendor onboarding is already mature. What comes next is expanding 3P inventory—critical for fueling retail media monetization. Bernstein estimates retail media revenue could grow from 3% to 5% of GMV, implying a $10 billion annual revenue stream.

For investors tracking Walmart's e-commerce and advertising efficiency, the Full Financials as Reported API helps dissect evolving cost structures, digital gross margins, and ad revenue contributions.

Target: Roundel's Rapid Rise with Structural Limits

Target's Roundel ad business already accounts for 9% of its e-commerce GMV, and the company wants to push that figure to $4 billion by 2029—an 11% share, surpassing Amazon's 7% benchmark.

This is a high-growth target, but it's not without risk. Bernstein raises concerns over potential cannibalization of traditional trade spend and the limited scalability of Target Plus, the company's invite-only 3P marketplace.

That poses a challenge: Can Roundel continue growing without eroding profitability or saturating GMV? Investors can track retail trends, margin expansion, and quarterly GMV shifts using the Retailing Industry P/E Ratio API to evaluate if Target's valuation reflects realistic ad-driven upside.

Costco: Underrated Contender with Curated Strength

Costco may be behind in retail media scale, but its steady hand in monetizing adjacent revenue streams—like travel, gas, and optical—makes its $340 million ad business a base worth building on.

Bernstein projects Costco could grow that figure to $1 billion by 2029, even with structural constraints like a small SKU count and curated 3P inventory (Costco Next).

More importantly, ad growth could improve operating margins by 10 bps—a meaningful shift in a business that typically runs on 2-3% margins. And with 1P e-commerce projected to rise from 9% to 15% by 2029, digital monetization will be more about depth than scale.

Final Thought

Retail media isn't just about advertising anymore—it's reshaping how legacy retailers monetize data, margins, and distribution at scale. For Walmart, Target, and Costco, success in this space could define their e-commerce profitability and market positioning over the next decade.

And for investors, tracking gross margins, GMV growth, and retail sector valuations through FMP tools like the Full Financials API and Retail P/E API is essential for staying ahead of this $100 billion media revolution.