You’ve sat through the slides: glossy charts, cherry-picked testimonials, and a single case study with a 400% return on ad spend. You asked for numbers and got “benchmarks.” You wanted raw data and got screenshots cropped to look impressive. If you want proof, not promises, this guide gives a repeatable, evidence-first method you can use tomorrow — including the exact citation tracker templates, validation checks, and an interactive self-assessment to score any vendor pitch.
1) Define the problem clearly
The problem: vendors present persuasive narratives without verifiable, reproducible evidence. That leads to buying decisions based on anecdotes, not causation. You need verifiable case studies with raw metrics, proper attribution, and methods you can audit.
- Common symptoms you already see: vague “uplifts,” unlinked screenshots, no time-window or sample-size details, and a refusal to share tracking access. Short form: talk (claims) ≠ tracked evidence (proof).
2) Why this matters
Every unverified promise is a budget leak. When decision-making is driven by unproven claims, you compound risk: overspend on ineffective tools, excuse poor vendor performance, and create repeated procurement failures. The effect is measurable — lower ROI, longer payback periods, and higher churn on marginal initiatives.
Concrete consequences:
- Cost-per-acquisition (CPA) inflation — you pay more for the same volume of customers. Opportunity cost — funds tied up in unproductive pilots can't go to proven channels. Procurement fatigue — repeated procurement cycles with no lift diminishes willingness to test new ideas.
Cause → Effect in brief
- Cause: Vendors present aggregate percentage increases without sample size. → Effect: You overestimate significance — likely spending on noise. Cause: No access to raw event logs or tag manager. → Effect: You cannot independently verify attribution or dedupe conversions. Cause: Short test windows and single-cohort reporting. → Effect: Results are non-replicable and likely due to seasonality or outliers.
3) Analyze root causes
Root causes fall into three buckets: methodological, technical, and commercial.
Methodological causes
- Small or unreported sample sizes — the vendor reports percent lifts without telling you N (users, sessions, impressions). No control group or poor experimental design — confounding variables (promotions, creative changes) go unaccounted for. Cherry-picking time windows — selecting the exact period where the KPI spiked.
Technical causes
- Attribution ambiguity — multi-touch versus last-click, different lookback windows, and cross-device issues. Tracking gaps — missing server-side logs, duplicated events from multiple tags, or sampling in analytics. Opaque data pipelines — vendor dashboards that transform metrics without showing raw event counts.
Commercial causes
- Incentive misalignment — vendors benefit from reporting inflated relative lifts rather than sustainable absolute gains. Fear of revealing process — vendors may view raw data as IP and refuse sharing, creating information asymmetry.
4) Present the solution
Solution summary: demand reproducible case studies, require raw metrics with context, use a citation source tracker, and run simple validation tests before committing budget. Below is a pragmatic, auditable framework you can insert into your vendor RFP and vendor evaluation checklist today.
Core requirements to demand
Raw metric table for each case study (daily granularity, at least 90-day pre/post or A/B split), including N, conversion events, conversion rate, CPA, spend, and LTV where available. Attribution method and lookback window stated explicitly (e.g., 7-day click, 1-day view, server-to-server attribution). Access to dashboards and read-only user views, or delivered CSV exports of raw events. Screenshot archives with timestamps and the exact query used to generate them. A citation source tracker that ties every claim to a source file, URL, or screenshot you can open and verify.What a valid case study must include (minimum)
- Baseline period metrics (KPIs, averages, variance) Test period metrics with daily data Exact dates and timezone Sample size per cohort Statistical significance calculation or confidence intervals Attribution rules and deduplication logic
5) Implementation steps — step-by-step with checks
Use this playbook during vendor evaluation and in contracts. Each step includes what to ask for and how to verify it.
Step 1 — RFP & mandatory evidence clause
Insert a clause: "All case studies must include raw daily-level export (CSV) for the date ranges, plus attribution logic and screenshot archive." Require a citation source tracker as part of the submission (template below).Step 2 — Initial evidence review (5-10 minutes)
What to check immediately:
- Are dates present? If not, reject as incomplete. Is N (sample size) stated? If not, ask for raw event counts. Is the attribution window and model explicit? If not, ask for clarification.
Step 3 — Quick validation tests (30–90 minutes)
Request raw CSVs and run a simple pre/post comparison: compute mean and variance for KPI; check if uplift is outside baseline variance. Check attribution by matching conversion timestamps to click IDs or session IDs (ask for a mapping file if needed). Look for unnatural spikes in daily data consistent with reporting interpolation (e.g., flat lines, sudden 100% jumps).Step 4 — Technical audit (if you move forward)
- Grant read-only access to analytics (GA4/UA), ad platforms, and server logs for the relevant dates. Verify event deduplication rules. Run a sample reconciliation: total conversions in vendor CSV vs your analytics and server logs. Accept discrepancies ≤5% (depending on channel); anything larger needs an explanation.
Step 5 — Contractual guardrails
- Define success metrics, test windows, and minimum sample sizes in the SOW. Include a clause that final payment is contingent on passing an independent reconciliation and meeting pre-defined effect sizes or replication tests.
Step 6 — Ongoing verification
- Ask for daily/weekly CSV exports for the first 90 days of any engagement. Automate the import into a spreadsheet and run a verification script to flag anomalies. Keep the citation source tracker updated and require screenshot exports at agreed intervals.
Citation Source Tracker — Plug-and-play table
Claim Source Type Source URL / File Screenshot Filename / Timestamp Verifier Notes +28% conversion rate (Campaign A) CSV export (daily) /evidence/campaignA_daily.csv campaignA_2025-10-01_09-15.png Verified counts matched analytics within 3% across 90 daysUse the table above to force traceability. If a claim cannot point to a line in a CSV or a stored screenshot with a timestamp, treat it https://milolrbu501.raidersfanteamshop.com/faii-for-local-businesses-mastering-local-seo-and-ai-visibility-management as unsupported.
6) Expected outcomes — what validated proof looks like
When you implement the framework, here’s what you should expect to see and why those outcomes matter.
Outcome Typical magnitude Why this matters (cause → effect) Reduction in vendor-claimed lifts that fail verification 30–60% of claims audited are partially or wholly unsupported Cause: prior claims relied on selective windows. Effect: you avoid spending on unreliable strategies and reduce wasted pilots. Improved contract terms (paid on verified metrics) Shift to 10–30% holdback until metrics verified Cause: contractual guardrails align incentives. Effect: vendors invest in clean setups and maintainable tracking. Higher percentage of repeatable wins Verified projects replicate at least 70% of reported effect Cause: better selection and audit. Effect: your portfolio of vendors yields more predictable ROI.
How to interpret numbers — a quick primer
Don't judge a vendor by percentage lift alone. Translate percentage lifts into absolute outcomes your budget team cares about. Use these formulas:
- Absolute increase in conversions = baseline_conversions × (lift %). New CPA = (baseline_spend + additional_spend) / (baseline_conversions + absolute_increase_in_conversions). Payback period = incremental_cost / incremental_monthly_profit (where profit = incremental_conversions × average_order_margin).
Example: baseline 1,000 conversions/month, average order margin $50, vendor claims +20% conversions. Absolute increase = 200 conversions. If implementation costs $10,000 and margin is $50, payback = 10,000 / (200×50) = 1 month.
Interactive self-assessments
Quick quiz: Is this vendor claim trustworthy? (Score 0–5)
Does the vendor provide raw daily-level data for the case study? (Yes = 1, No = 0) Is the sample size (N) explicitly listed? (Yes = 1, No = 0) Are attribution rules and lookback windows documented? (Yes = 1, No = 0) Is there a screenshot archive with timestamps and the exact query? (Yes = 1, No = 0) Does your analytics reconcile with the vendor’s numbers within an acceptable tolerance? (Yes = 1, No = 0)Scoring guide:
- 0–1: Reject. The evidence is insufficient. 2–3: Conditional. Require further proof, access, or a short pilot with verification clauses. 4–5: Proceed with pilot or small contract with verification milestones.
Self-assessment checklist (copyable)
- Case study includes pre/post or A/B with dates and CSV — checkbox Attribution model explicitly documented — checkbox Read-only access to analytics or exported raw events provided — checkbox Reconciliation run and variance ≤5–10% — checkbox Statistical significance or confidence intervals provided — checkbox
Expert tips & advanced checks
- Always ask for raw click IDs, session IDs, or hashed user IDs — these let you match events across systems and avoid double-counting. Request daily churned cohort tables — if uplift disappears after 7 days, it’s a retention issue, not acquisition success. Insist on pre-registration of the test plan when possible (dates, metrics, success criteria). This prevents post-hoc window fishing. Know your minimum detectable effect (MDE) before a test. If the vendor's claimed lift is smaller than your MDE given expected traffic, it’s indistinguishable from noise.
Final checklist before you sign
Do you have raw data exports (CSV) and access to dashboards for the representative case study? — Yes / No Can the vendor explain attribution and deduplication with examples? — Yes / No Are success metrics, sample sizes, and lookback windows in the contract? — Yes / No Is payment or bonus tied to verified outcomes? — Yes / No Do you have a citation source tracker populated for all claims? — Yes / NoIf you answered “No” to any critical items above, pause. Ask for the missing evidence. The power of this approach is not to be punitive — it’s to create reproducible, auditable results so budgets go to work where they actually move the needle.
Closing (what you can do next)
Start with the citation source tracker and RFP clause. Use the quick quiz as a gate for any vendor meeting. Require a 90-day pilot with daily CSV export and a 10–30% holdback until reconciliation. Over time, these small process changes will shift vendor behavior toward transparency and measurable outcomes.
Proof is not a negotiation tactic — it’s a procurement standard. Require it, verify it, and pay on it. Your budget will thank you.