How a Retail Giant Cut Ad Waste by 39% in 90 Days

NationalMart, a Fortune 500 retailer with 1,200+ stores across 48 states, was spending $180M annually on digital advertising — and their analytics team suspected at least a third of it was wasted.

The Challenge

NationalMart's marketing team was running campaigns across 15 DSPs, 8 social platforms, and 4 retail media networks. Each channel used its own audience taxonomy and measurement framework, making it impossible to see the full picture.

Key symptoms:

• Overlapping audiences across channels with no deduplication
• 40% of display impressions served to existing loyalty members who would have purchased anyway
• No ability to suppress recent converters across channels
• Inconsistent measurement — each platform claimed credit for the same conversions

The Approach

NationalMart deployed Datadek in a three-phase rollout over 90 days:

Phase 1: Audit (Weeks 1-3)

Connected all 27 ad platforms to Datadek's audience intelligence layer. Within two weeks, the team had a unified view of audience overlap, frequency distribution, and conversion deduplication across every channel.

Phase 2: Optimization (Weeks 4-8)

Using Datadek's audience segmentation, NationalMart built 48 precision segments combining first-party transaction data, loyalty program status, and third-party behavioral signals. They implemented global suppression rules for recent converters and established frequency caps that spanned all channels.

Phase 3: Activation (Weeks 9-12)

Segments were pushed to activation channels through Datadek's 143 platform integrations. The team set up incrementality measurement using geo-matched holdout groups to validate true uplift.

The Results (90 Days)

• 39% reduction in total ad spend with flat or improved revenue
• 2.1x improvement in incremental ROAS as measured by geo-holdout testing
• 55% reduction in wasted impressions (defined as impressions served to existing loyalty members or recent converters)
• Unified audience view across all 27 platforms, updated daily

What The Team Says

"Our media agency told us we needed to spend more to grow. Datadek showed us we needed to spend smarter. We cut nearly 40% of our budget and grew revenue by 8% in the same quarter. Our CFO now asks about Datadek dashboards in every marketing review."

The full case study, including detailed methodology and segment definitions, is available on our resources page.