Metric investigation: why 23andMe's conversion rate fell by a third
Company: 23andMe
Role: Product Manager
Category: Analytics & Experimentation
Difficulty: medium
Interview Round: Other
23andMe's conversion has fallen by 33%. Explain how you would find out why, and what you would do once you knew.
```hint Locate the drop before explaining it
Settle which conversion fell, over which window, and whether the change is real. Then cut it along the dimensions where a single cause would show up as a concentrated drop.
```
### Clarifying Questions
- Which conversion is this: website visitors buying a kit, buyers registering and returning their kit, or customers upgrading to the paid membership?
- Is the 33% a relative fall (for example from 3% to 2%) or a drop in percentage points, and what period is it compared with?
- Did the drop happen suddenly on one day, or build up over weeks?
- Did visits or orders change too, or only the rate?
### What a Strong Answer Covers
- Defining the metric precisely and confirming the drop is real, not a tracking or definition change
- A structured split: numerator versus denominator, traffic source, funnel step, device, geography, product and new versus returning visitors
- Internal causes such as releases, pricing, checkout, experiments and fulfillment checked before external ones such as seasonality, competitors and news
- Hypotheses specific to a consumer genetic-testing business, such as privacy trust, gift-driven seasonality and promotional calendars
- A plan to confirm the cause, a fix or mitigation, and the metrics that show recovery
### Follow-up Questions
- The whole drop comes from one paid channel and revenue is flat. What do you do next, and is it still a problem?
- If the cause were lost trust after privacy news, what product changes would you test to win it back?
- How would you tell a post-holiday dip from a lasting decline?
Overview: A 23andMe product manager interview question about diagnosing a 33% drop in conversion. It tests how a candidate validates the metric, splits the funnel and traffic mix, separates internal from external causes in a consumer genetic-testing business, and plans how to confirm and fix the cause.