Sizing New York City Demand for a New Bike-Share App: Residents, Commuters, Visitors
Company: Google
Role: Product Manager
Category: Product / Decision Making
Difficulty: medium
Interview Round: Other
Suppose you are launching a bike-sharing app in New York City. Estimate how many people would be interested in using it, walk through your structure, assumptions and arithmetic, and check whether your answer is reasonable.
```hint Define "interested" before you multiply
Decide whether you are counting people who would try the service at least once or people who would ride regularly, then build the estimate from the groups who actually make bike-friendly trips in the city rather than applying one percentage to the whole population.
```
### Clarifying Questions
- Does "interested" mean people who would install the app and take at least one ride in its first year, or people who would ride regularly?
- Should the count include only city residents, or also people who commute in from outside the city and tourists?
- Does the launch come with our own fleet of bikes, and does that fleet include electric bikes?
- Should the estimate cover interest in bike sharing overall, or only the share a new service could win, given that the city already has a large bike-share system?
### What a Strong Answer Covers
- A precise definition of "interested" and of the population in scope, agreed before any arithmetic.
- A segmented structure (residents filtered by age, willingness to ride and trip fit, plus in-commuters and visitors) rather than a single top-down percentage.
- Round-number assumptions, each labeled and briefly justified, with arithmetic that is easy to follow.
- A sanity check against an independent anchor, and a range that shows which assumptions matter most.
- What the number means for the launch, such as where to start, how seasonality matters and how much of the interest a new entrant can capture.
### Follow-up Questions
- How would your estimate change between July and January, and what does that mean for how many bikes you need?
- How would you turn the number of interested people into the number of bikes needed at launch?
- Which neighborhoods would you launch in first, and what data would you use to choose them?
Overview: A product manager estimation question about sizing how many people in New York City would be interested in a newly launched bike-sharing app. It tests structured market sizing: defining interest, segmenting residents, in-commuters and visitors, stating round-number assumptions, keeping the arithmetic clean and sanity-checking the result.