Level 2 of Sarah Tavel’s Hierarchy of Engagement focuses on retention—keeping users coming back. She breaks this down into two powerful mechanisms: Accruing Benefits and Mounting Losses.
Accruing Benefits
“The more someone uses the product, the better it gets.”
As users add data to your product—explicitly or implicitly—the product should use this data to improve their experience.
Examples:
- Pinterest: The more you pin, the better Pinterest understands your interests → better recommendations → more relevant discovery feed
- Spotify: The more you listen, the better your Discover Weekly and personalized playlists become
- Google Maps: The more you use it, the better it predicts your commute times and suggests relevant places
- Amazon: Purchase and browse history improves recommendations
The key is that value compounds over time. Day 1 users get a generic experience; Day 100 users get a personalized one that’s measurably better.
Mounting Losses
“The more someone uses the product, the more they would lose if they left.”
This creates natural switching costs—not through lock-in tactics, but through accumulated value.
Examples:
- Evernote: Years of notes, organized into notebooks, with internal links. Leaving means losing your second brain.
- Notion: Wikis, databases, workflows—your team’s entire knowledge base is there
- Salesforce: Years of customer data, custom fields, integrations, workflows
- Pinterest: Your curated boards represent hours of curation
The longer someone stays, the more the product becomes something they depend on.
The Interplay
The magic happens when both work together:
- Accruing Benefits create the positive pull (product gets better)
- Mounting Losses create the switching cost (too much to lose)
Pinterest achieves both: your pins make the product better for you (accruing benefits), AND your curated boards represent value you’d lose (mounting losses).
The Evernote Warning
Evernote nailed Level 1 (core action: creating notes) and Level 2 (strong accruing benefits and mounting losses). But they never achieved Level 3—there are no network effects. Your notes don’t make the product better for anyone else.
Result: Growth plateaued. They had sticky users but no flywheel for growth.
Practical Questions
When designing for Level 2, ask:
- What data can users accumulate that makes the product better for them?
- What would users lose if they switched? Is it significant enough?
- Are you creating genuine value, or just artificial switching costs?
The third question matters for ethics. There’s a difference between “you’d lose all your curated content” (legitimate value) and “we make it hard to export your data” (hostage-taking).
How do you think about building accruing benefits and mounting losses in your products? Where’s the ethical line?