The Chart That Manufactured a Trend

1. The truncated y-axis (9.8k–11.2k). The series moves about 1,100 users, roughly 11%, but against a 1.4k window it renders as a near-vertical climb. This is the most damaging item because it is the one that survives a screenshot. Fix: start the axis at zero for a bar chart, or keep a line chart with the axis range stated on the chart and the delta annotated directly - "+1.1k users, +11% over 12 months."

2. The title asserts a conclusion. "Explosive" is a judgement smuggled into a label, and for a series that rises ~1% a month, most readers would not agree with it. Fix: title the finding, not the hype - "MAU grew 11% over 12 months, roughly 1.1k users (10.0k → 11.1k)."

3. The 3D exploded pie. Pies are hard to compare beyond three or four slices, 3D tilts distort the areas, and the explosion draws attention arbitrarily. Fix: a sorted horizontal bar chart; it is readable in a projected slide and rank order is the point.

4. The rainbow palette. Colour is carrying no information - it just adds noise and fails for colour-blind viewers. Fix: one accent colour for the series or the highlighted channel, grey for the rest.

Judgement: the chart is not merely ugly; the axis choice changes the conclusion a busy executive will draw in six minutes.

Not directly, and say so clearly. The honest answer separates three things:

1. What the chart shows: MAU rose ~11% over 12 months. That is descriptive, and it is real - but it is a change over time, not a campaign effect. Nothing in this series isolates the campaign from seasonality (the pattern is suspiciously sawtooth: up in even months, flat or down after), from product changes, or from ordinary market growth.
2. What it does not show: whether the growth is incremental, whether those users retained or converted to revenue, and whether $200,000 would buy more of it. MAU is a reach metric, not a value metric.
3. What would answer the question: a comparison - a geo holdout, a pre/post test with a control group, or a prior campaign's lift measured the same way - plus expected incremental revenue per acquired user and retention over at least one cohort cycle.

Judgement: the credibility cost of answering "yes" and being wrong once is higher than the cost of asking for a test. With a sceptical CFO, "here is the test I would run and what it would cost" is a stronger answer than an optimistic chart.

One slide, one chart, one recommendation.

• Title (takeaway, not topic): "MAU is up 11% over 12 months, but growth is flat month-to-month - no evidence yet that it is campaign-driven."
• Single chart: line of MAU with the axis range labelled, plus a shaded or annotated region showing when the prior campaign ran (or a note that none did). One accent colour. No pie, no 3D, no rainbow.
• One-line annotation at the point of change: "+1.1k users, 10.0k → 11.1k."
• Footnote: definition of MAU ("distinct users with a session in a calendar month"), date range, n, and the data source - because a metric with no definition on the slide will be re-litigated in Q&A.
• Ask, stated explicitly: "Approve a four-week geo holdout ($18k of the $200k) to measure incremental lift before committing the remainder."

Why this survives the CFO: it shows the number, the limitation, and the decision in one glance, and every claim on it is traceable. It also pre-empts the question she is most likely to ask - "compared to what?" - which the annotation answers before she asks it.