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Case Study

Baselines, Retention and the Problem With Vanity Metrics

A walkthrough of one funded programme whose headline numbers were accurate and almost entirely uninformative.

Jonas BergReviewed by Priya Raman13 min readPublished 5/28/2026Updated 6/15/2026
All research

Key points

  • Impressions and sign-ups without a baseline cannot show impact.
  • Retention at day 30 changed the reading of the programme entirely.
  • The programme was not dishonest; the metrics were simply the wrong ones.

The reported numbers

The final report led with 42,000 impressions and 3,100 sign-ups. Both figures were verifiable and neither was contested.

What a baseline would have shown

Sign-ups in the preceding quarter, absent the programme, ran at roughly two-thirds of that rate. The incremental effect was real but far smaller than the headline implies.

The fair reading

This is a measurement design problem, not a misconduct finding. The programme was asked for the wrong evidence and supplied it faithfully.

What we could not establish

  • No control region was available, so counterfactual impact remains an estimate.

Sources and references

  1. [1]Programme final report - Source link placeholder
  2. [2]Baseline extract and method note - Source link placeholder
JB

Author

Jonas Berg

Measurement contributor

Builds attribution and measurement frameworks for consumer platforms.

PR

Reviewer

Priya Raman

Reviewer, data science

Checks whether the numbers support the claim being made with them.

Related

  • Metrics sanity-check checklist

    Resource library

  • Data & Evidence track

    DRep Academy