Daily Active Users
How research revealed that casual sellers, not power users, held the key to daily engagement
Driving Daily Active User Growth on Mercari Through User-Centered Insights
At first glance, the problem seemed straightforward: Mercari's US users checked the app once or twice a week, while Japanese users visited daily. The obvious solution? Get more power sellers. But as I dug into the research, a different story emerged – one where casual sellers and serendipitous discoveries were creating some of our most engaging marketplace moments. Here's how our research journey transformed Mercari's approach to user engagement and led to a 25% increase in daily active users.
Company
Mercari US
Timeframe
Feb - Apr 2023
Role
UX Researcher
The Challenge
Our challenge wasn't just about gathering data – it was about finding the right data. With 80,000 daily active users in the US, we needed to understand what truly drove engagement without getting lost in the numbers.
Research Decisions that Mattered
Defining "highly engaged": Finding the people behind the metrics
One of my first crucial decisions was how to identify truly engaged users. Working with our data science team, I pushed for a more nuanced definition: users active for 60+ days within a quarter. This helped us focus on sustained engagement rather than just frequent usage.
Balancing depth vs. scale
I designed a mixed-methods approach that would give us both breadth and depth:
- Large-scale surveys for pattern identification
- Week-long diary studies for behavioral insights
- In-depth interviews for context and motivation
Research Process Timeline
Getting creative with limited tools
I looked into diary study tools, but onboarding a new vendor would have taken too much time. When our usual research tools hit their limits, I had to get scrappy:
- Set up individual Google Drive folders for diary submissions
- Created daily in-app survey prompts to maintain engagement
- Built custom synthesis frameworks incorporating diary study data and interview notes in EnjoyHQ
Qualitative coding in EnjoyHQ, survey synthesis showing themes from Product-Market fit analysis, and summary slides highlighting Mercari's key value proposition for the executive share-out.
The observer effect
A critical challenge in the diary study was observation bias – participants' behavior often changes when they know they're being studied. I developed a systematic approach to validate our findings:
- Created a Looker dashboard to compare each participant's app usage patterns 30 days before and during the study
- Identified which behaviors were genuine vs. "performance" by looking for significant pattern changes
- Cross-referenced interview insights with actual platform behavior
Unexpected Insights
Our research revealed three surprising patterns that challenged our assumptions:
- The casual seller effect: The data showed something unexpected: casual sellers, not power users, were creating some of our most engaging marketplace moments. Their occasional mispricing of items created "treasure hunt" opportunities that kept buyers coming back daily.
- The trust paradox: While we'd been focused on building social features, users were forming stronger connections through simple transaction-based interactions. A thank-you note meant more than any social networking tool.
- The emotional investment: Our rating system had evolved beyond its original purpose. Rather than just indicating trust, it had become an emotional anchor that kept users invested in the platform.
Turning Insights into Action
After presenting these findings to product management and the executive team, this research led to several key initiatives:
Product changes
- Added community hashtags for niche interests
- Enhanced ratings tools to build trust
- Introduced 'lite listing' for casual sellers
- Doubled down on saved search functionality, which contributes to 85% of app GMV
- Investment in information architecture to maintain simplicity
Saved search revamp
Before: The saved search experience prior to the revamp was a cold start, difficult to organize, and didn't provide clear visual cues when new items were listed that matched a saved search.
After: The new saved search experience improved visual cues, encouraged adoption amongst new users, and provided ways for users to visually prioritize their most important searches.
Communities launch
Communities was a feature in development to promote purposeful communication, helping people communicate to spur more treasure hunting.
Marketing shifts
- Emphasized the thrill of deal-finding
- Highlighted the authenticity of casual sellers
- Focused on trust-building features
Current App Store screenshots emphasizing deal-finding, authenticity, and simplicity
Impact and Results
The research directly influenced Mercari's strategy in two crucial ways:
Metrics and engagement:
- 25% increase in daily active users over one year
- 12-47% GMV growth in key verticals
- 9% increase in Start Your Search
- Significantly higher listings per new seller in Japan
Strategic Direction:
Our findings helped maintain product focus during a critical moment. While there was organizational pressure to expand into social features, our research clearly showed users valued Mercari's simplicity and straightforward commerce experience. I recommended prioritizing information architecture improvements over new social features, backing this with data showing:
- Users primarily wanted clear, efficient buying and selling
- Existing transaction-based interactions already created meaningful connections
- App simplicity was actually a key differentiator for our users
This study catalyzed impact through experience changes, new technical requirements, identification of growth opportunities, and risk mitigation strategy.
The Bigger Picture
This project taught me that sometimes the most valuable insights come from questioning our initial assumptions and being willing to follow the data, even when it leads in unexpected directions. By remaining flexible in our methods while maintaining research rigor, we uncovered insights that transformed not just metrics, but the entire user experience.
Looking Forward
The frameworks and methodologies we developed have broad applications for marketplace platforms, particularly in situations where user behavior is driven by complex emotional and social factors. I'm excited to apply these lessons to new challenges in understanding and enhancing user engagement.
