case studyprincipal mediareporting

Case Study Template: Demonstrating ROI When You Increase Transparency in Principal Media Deals

UUnknown

2026-02-17

9 min read

A repeatable case study template for advertisers and agencies to prove transparency ROI in principal media buys and improve attribution.

Hook: If your media buys feel like a black box, this template proves the value of shining a light

Advertisers and agencies still lose budget to opaque processes, mismatched attribution, and unverifiable supply chains. You need a repeatable way to show transparency ROI when you implement verification in principal media buys. This case study template is designed for marketing teams and agency partners to document improvements, quantify wins, and secure buy-in from procurement and finance.

Why this matters in 2026

Two important developments in late 2025 and early 2026 make this template timely. Forrester's 2026 analysis confirmed that principal media is here to stay, but it recommended stricter transparency controls and measurable verification to reduce leakage and conflict of interest. At the same time, platform controls like Google's total campaign budgets for Search and Shopping (rolled out in Jan 2026) changed campaign pacing, increasing the need for accurate verification to ensure optimized spend is delivering the promised outcomes.

Forrester (Jan 2026): principal media will grow — the differentiator will be how transparently it's executed and measured

What this article gives you

This is not theory. It's a practical, repeatable case study template you can run across clients and campaigns to show the concrete impact of:

Implementing media buy verification tools and processes
Closing visibility gaps around fees, reseller margins, and ad delivery
Improving attribution and incrementality measurement

Overview: The principal media case study framework

Use this framework as a checklist and narrative structure for each case study. Replace examples with your client data and include raw exports in an appendix for audits.

Executive summary — Key outcomes: % improvement in CPA, reduction in invalid traffic, and net transparency ROI.
Background & objectives — Client profile, campaign goals, baseline issues (opacity, attribution gaps).
Intervention — Changes: third-party verification, server-side tracking, S2S bidstreams, contractual transparency clauses.
Measurement plan — KPIs, time windows, data sources (ad logs, server logs, clean room), attribution models tested.
Results — Data visualizations, statistical tests, and the calculated transparency ROI.
Learnings & recommendations — Operational changes, contract updates, future tests.
Appendix — Raw tables, verification provider reports, legal clauses, and reproducible queries.

Step-by-step case study template (copyable)

1. Executive summary (one paragraph)

Start with three numbers: the improvement in core KPI (CPA or ROAS), the reduction in leakage or IVT, and the net transparency ROI. Example: "After verification, CPA fell 22%, invalid traffic declined 46%, delivering a 3.7x transparency ROI over 90 days." Keep this headline tight — executives read only the top.

2. Situation and objectives

Describe the campaign and the problem you addressed. Include:

Client vertical, media spend, platforms, and contract type (principal/reseller).
Baseline KPIs: spend, CPA, CTR, viewability, percent IVT, attribution model used.
Business goals: reduce waste, improve attribution, or raise conversion volume without increasing budget.

3. Baseline measurement (what to capture)

Collect 30-90 days of baseline data before intervention. Export and store raw data. Essential metrics:

Media spend by line item and placement
Impressions, clicks, viewability
Invalid traffic (IVT) and fraud-related deductions
Conversion events and purchase values
Attribution credits under current model(s)
Effective CPM (eCPM) and net CPM after fees

4. Intervention: What you changed

Be explicit. The stronger the description, the easier to replicate.

Implemented third-party verification from vendors like DoubleVerify, IAS, or Oracle Moat to measure viewability and IVT.
Enabled bidstream transparency and periodic log files from principal partners.
Shifted to server-side tracking and S2S conversions with hashed identifiers to improve data fidelity.
Introduced contractual clauses for resellers: pass-through fees, unified reconciliation cadence.
Run an incrementality experiment (holdout or geo-based test) to isolate causal lift.

5. Measurement and verification plan

Document the methodology so auditors can reproduce results. Include:

Time windows for pre/post comparisons and test/control.
Attribution models used: existing (e.g., last-click) and new (data-driven, MMM, or incrementality).
Data sources: ad server logs, verification vendor CSVs, analytics platforms, CRM match rates, clean room outputs.
Statistical tests: confidence intervals, p-values for conversion lift, and minimum detectable effect (include your statistical tests and methodology).

6. Results: metrics to report

Present absolute and relative changes. These are the metrics buyers and procurement want to see:

CPA / CPC / CPM before and after
Conversion rate and incremental conversions measured via holdout
IVT & fraud reduction percentage
Viewability increase (percentage of measurable impressions)
Attribution improvements — delta in conversions credited when moving to data-driven or incrementality-based models
Transparency ROI — a formula below

7. Transparency ROI: a repeatable formula

Calculate a conservative ROI that finance can understand. Use three components:

Direct savings from reduced waste (S): baseline spend attributable to IVT or non-viewable impressions multiplied by % reduction
Incremental revenue from lift (L): incremental conversions times average order value times contribution margin
Implementation cost (C): verification tools, integration, staff time, and one-off legal changes

Transparency ROI = (S + L - C) / C

Example: Baseline IVT exposure is $200k a month. Verification reduces IVT by 40%, saving $80k. Incremental conversions produce $120k in gross profit. Implementation costs are $50k. ROI = (80k + 120k - 50k) / 50k = 3.0x.

8. Attribution improvements and why they matter

Moving from opaque last-click attribution to a combination of data-driven and experimental incrementality testing changes budget allocation. Document:

How many conversions moved from last-click to assisted credit
Changes in channel ROAS under new models
How the sum of model credits aligns with incrementality test results

Practical verification checklist

Make this checklist a standard inclusion in your case study appendix. It saves time and prevents disputes.

Obtain native ad server logs and cross-check bidstream timestamps
Ingest verification vendor CSVs with impression-level verdicts
Run matching logic between ad logs and analytics for conversion attribution
Use a clean room to join CRM and publisher data when PII is required
Document contractual fee pass-through and reconcile invoices and keep an auditable audit trail

Data visualization recommendations (what to include)

Visuals turn metrics into narratives. Include these visuals in the results section:

Time-series of CPA and spend with the intervention marker
Stacked bar for spend by placement showing reclaimed spend from IVT
Lift chart comparing conversion rates in test vs. control
Pie chart of attribution credit distribution before and after

Sample ad performance case study (compact example)

Client: Direct-to-consumer fitness brand. Monthly media spend: $500,000. Issue: High non-viewable impressions and unclear reseller fees.

Intervention: Added third-party verification (DoubleVerify), enabled S2S conversions, and included a 30% media holdout for incrementality testing. Reconciled fees with publisher logs.

Results (90 days):

IVT dropped from 7% to 2% (reclaimable spend saved: $25k/month)
Viewability improved 18 percentage points
Incremental conversions (holdout) produced 420 additional purchases with AOV $110 and 40% gross margin = $18,480 incremental gross profit/month
Implementation & verification fees: $12,000 one-time + $5,000/month platform fees

Transparency ROI (first 90 days) = ((25k*3 months) + (18,480*3) - 12k) / (12k + 15k) = ((75k + 55,440 - 12k) / 27k) ≈ 4.3x

This is the kind of headline that wins procurement support.

How to present this to clients and procurement

Procurement looks for reproducibility and conservative assumptions. Use these tactics:

Provide raw exports and the SQL/BigQuery/Snowflake queries used to calculate metrics.
Show sensitivity analysis — best, base, and conservative cases.
Document the audit trail: who had access, when logs were pulled, and verification vendor certificates (TAG accreditation, SOC2, etc.).
Recommend contract language for future principal buys: mandatory logs, pass-through fees, monthly reconciliations, right to audit.

2026 toolset and vendor guidance

By 2026, vendors have matured. Recommended stack for agencies running these case studies:

Verification: DoubleVerify, IAS, Oracle Moat — use a primary and a secondary for cross-validation.
Identity & matching: LiveRamp or Snowplow for clean-room joins.
Data warehouse: BigQuery or Snowflake for hosting raw logs and running reproducible queries.
Experimentation: Holdout frameworks in Google Ads (with total campaign budgets) or server-side feature flags for geo-based tests.
Measurement partners: An independent econometrician for MMM and a measurement partner for incrementality when scale requires it.

Common objections and rebuttals

Procurement and clients will push back. Here are short rebuttals you can use in decks.

Objection: "Verification is too expensive." Rebuttal: "Calculate transparency ROI; even modest reductions in waste typically pay back within one quarter."
Objection: "We already have reporting." Rebuttal: "Existing reporting often misses the supply path and invisible fees. This is about reconciliable, auditable data."
Objection: "Attribution changes are disruptive." Rebuttal: "Run side-by-side models and holdouts so budget moves are evidence-led, not anecdotal."

Template: Client reporting template (sections to deliver)

Use this as your standardized client report format. Deliver weekly snapshots and a quarterly case study dossier.

Cover: Campaign name, date range, spend summary
Executive summary: 3-line performance headline
Baseline vs post-intervention table
Key visualizations and variance analysis
Transparency ROI calculation and assumptions
Attribution model comparison and reconciliation
Audit appendix: raw files, vendor reports, contract summaries

Checklist for running the study in 8 weeks

Make the timeline executable. Target an 8-week minimum to allow for stabilization after changes.

Week 1: Baseline data pull and stakeholder alignment
Week 2: Contract updates and enable verification tags
Week 3: Implement server-side tracking and data pipelines
Week 4–6: Run campaigns with verification active and holdout running
Week 7: Data reconciliation and statistical analysis
Week 8: Present case study with appendix and next steps

Final checklist before you publish the case study

Have legal review anonymization if using client data publicly
Ensure all vendor logos are credited and permissions secured
Validate calculations with finance and the verification vendor
Include reproducible queries or a link to a data sandbox for audits

Closing: Why this wins long-term

In 2026, principal media is not going away. The winners will be those who convert opacity into verifiable, auditable outcomes. Use this case study template to institutionalize proof: you reduce waste, optimize budgets, and make attribution defensible. That combination buys you negotiating leverage and long-term client trust.

Actionable takeaways (quick list)

Collect a 30–90 day baseline and store raw logs.
Implement third-party verification and S2S tracking before concluding results.
Run a holdout or geo experiment to measure incrementality.
Report Transparency ROI with conservative assumptions and raw exports.
Include audit-ready appendices and contract language for future principal deals.

Call to action

Use this template on your next principal media engagement. If you want a fillable client reporting template and a sample BigQuery workbook that calculates transparency ROI automatically, contact our team or download the free toolkit linked from our agency page. Start turning media transparency into measurable business value today.

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