At a glance
- Role
- Product Manager, owned the feature end to end
- Team
- Me, as product manager, designer and engineer
- Timeline
- August 2024 to January 2026, then six months of post-implementation measurement
- Users
- Patients on a rare disease health platform, plus the research clients who rely on their data
- Metrics
- Weekly adoption 0.5% to 12%, held at 10% to 15% for six months
Problem and stakes
Daily Diary lets patients record how they feel each day: symptoms, energy, sleep and notes. For patients it is a record they can look back on. For our research clients it is the richest longitudinal data the platform produces, so low usage meant thinner studies and weaker evidence for the people funding them.
When I picked it up, about 0.5% of weekly active users touched it. Usage analysis pointed at discoverability: the entry point was buried, and most people never saw it. That was true, but it turned out to be only half of the problem.
What talking to patients changed
I ran a round of patient conversations before building anything. Patients who had tried the diary once told me they did not see enough value in what they had recorded to come back. A discoverability fix alone would have brought people in once and lost them again.
- "I filled it in for a week and then nothing happened. What was it for?"
- "I would do it if I could see whether my bad days line up with anything."
- 1 Post-login prompt and quick access · Apr 2025
- 2 Richer charts and notes · Aug 2025
- 3 Lifecycle emails · Oct 2025
View as table
| Month | Adoption | Change shipped |
|---|---|---|
| Aug 2024 | 0.5% | |
| Sep 2024 | 0.5% | |
| Oct 2024 | 0.5% | |
| Nov 2024 | 0.5% | |
| Dec 2024 | 0.6% | |
| Jan 2025 | 0.5% | |
| Feb 2025 | 0.5% | |
| Mar 2025 | 0.6% | |
| Apr 2025 | 0.8% | Post-login prompt and quick access |
| May 2025 | 3.2% | |
| Jun 2025 | 4.5% | |
| Jul 2025 | 5% | |
| Aug 2025 | 5.5% | Richer charts and notes |
| Sep 2025 | 7.5% | |
| Oct 2025 | 9% | Lifecycle emails |
| Nov 2025 | 10.5% | |
| Dec 2025 | 11.5% | |
| Jan 2026 | 12% | |
| Feb 2026 | 11% | |
| Mar 2026 | 13.5% | |
| Apr 2026 | 10.5% | |
| May 2026 | 14% | |
| Jun 2026 | 12.5% | |
| Jul 2026 | 12% |
What I did
-
01
Split the work by the problem it solved, not by the screen it touched
Two problems needed two kinds of fix. Finding the feature and having a reason to return are different jobs, and I wanted to be able to tell which change moved the number.
Tradeoff. Sequencing the releases slowed the headline number by a few weeks, but it meant the adoption chart could show what each change did.
-
02
Finding it: a post-login prompt that people can dismiss, plus persistent quick access
The prompt had to interrupt once and then get out of the way. A "don't show again" option kept it from becoming nagware, and a quick-access entry point gave people a path back after they dismissed it.
Tradeoff. Some teammates wanted the prompt to persist until the first entry. I argued that forcing it would cost us trust with exactly the patients we were trying to win.
-
03
A reason to return: richer charts and notes for reflection
Patients wanted to see patterns in their own data. Charts that showed a week or a month at a glance, with notes attached to the days that mattered, gave the diary a payoff beyond the act of filling it in.
Tradeoff. This was the most expensive piece of the work. I cut a planned export feature to make room for it, because reflection in the app was the thing patients had actually asked for.
-
04
Understanding the value: lifecycle emails that explained what tracking could show you
People who had never tried the diary did not know what they would learn from it. A short series of emails, timed to the first weeks after sign-up, explained the value in patients' own terms.
Tradeoff. Email volume is a sensitive thing on a health platform. I kept the series short and made every message easy to opt out of.
People could not find it
What the usage data showed.
- Post-login prompt with "don't show again"
- Persistent quick access to the diary
No reason to come back
What patients told me.
- Richer charts and notes for reflection
- Lifecycle emails explaining what tracking can show you
How I measured it, not only what I built
Each change shipped with a before-and-after comparison on weekly adoption, so the chart could show what each one did. After the last release I spent six months on the post-implementation data, watching whether adoption held rather than spiked, and ran a second round of patient interviews to check that the numbers meant what I thought they meant.
What went wrong
I did not set up the measurement before the first release. The post-login prompt shipped with the entry-point analytics still being wired, so for the first few weeks I could see adoption moving but could not cleanly tell how much came from the prompt and how much from quick access. I had to rebuild that view from raw events after the fact, and the later releases all shipped with their measurement in place first. The lesson I keep is that the before-and-after comparison is part of the feature, not something to add once it is live.
Results
- Weekly adoption rose from 0.5% to 12% of weekly active users.
- Adoption held between 10% and 15% for six months after the last change shipped. The holding number is the retention proof.
What I learned
Discovery gets someone to try a feature. Value gets them to return. You need both, and the dashboard will usually only show you the first one.
What I'd do next
- Test a weekly summary notification that shows the patient one pattern from their own data, to see whether it lifts the return rate further.
- Try a shorter first-run flow that asks for one data point instead of a full entry, and measure whether the easier start changes the six-month hold.
Why this matters
Activation, onboarding and lifecycle messaging sit at the centre of growth and self-serve PM roles. I have used lifecycle messaging to drive feature adoption, and I measured whether people kept coming back. The onboarding prompt pattern here (show once, let people dismiss it, keep a quick path back) is the same thinking any product's or agent's first-run experience needs.
Next case study
Community polls A/B test
I ran an A/B test on the email driving patients to a new community polling feature. The simpler version beat my own longer one, 31% participation to 18%, so it shipped and set the tone for the lifecycle emails that followed.
- A/B testing
- Lifecycle messaging
- Adoption
- Community