Choosing the Right Channel
Email, push notifications, and in-app messages each have distinct strengths. Using the wrong channel for a message does not just reduce effectiveness — it actively annoys users. The right channel depends on the urgency, complexity, and context of what you are communicating.
Push Notifications: Urgent and Brief
Push notifications interrupt whatever the user is doing. That interruption is powerful when warranted and irritating when it is not.
Use push for:
- Time-sensitive alerts (a deal expiring, a live event starting)
- Activity triggers (someone responded to their message, a workout reminder)
- Brief re-engagement nudges for lapsed users
- Transactional confirmations (payment received, subscription renewed)
Do not use push for:
- Long-form content or announcements
- Marketing messages that are not time-sensitive
- Anything that requires the user to read more than two sentences
Push notifications have the highest open rate of any channel (up to 10% to 20% on iOS with permission, higher on Android) but also the highest opt-out rate when overused. Treat every push notification as a withdrawal from your user's attention bank account.
In-App Messages: Contextual and Visual
In-app messages appear while the user is already engaged with your app. They have 100% visibility among active users and zero reach for inactive ones.
Use in-app for:
- Feature announcements and onboarding tips
- Upgrade prompts and paywall presentations
- Surveys and feedback requests
- Contextual tips related to what the user is currently doing
- Referral program invitations
Do not use in-app for:
- Reaching inactive or churned users
- Messages that need to be saved or referenced later
- Anything that requires action outside the app
In-app messages are ideal for affiliate program recruitment. When a user reaches a satisfaction milestone (completed a workout streak, finished a project, achieved a savings goal), an in-app message inviting them to join your affiliate program and earn by sharing the app is perfectly contextual.
Email: Detailed and Persistent
Email is the most flexible channel. It handles everything from brief transactional notices to detailed newsletters and sits in the user's inbox until they choose to engage with it.
Use email for:
- Onboarding sequences that span multiple days
- Product updates and feature announcements
- Monthly or weekly summaries (workout stats, spending reports)
- Re-engagement campaigns for churned users
- Affiliate program updates and performance reports
- Content that users might want to reference later
Do not use email for:
- Real-time alerts that need immediate attention
- Messages that make sense only within the app context
- High-frequency communications (daily emails burn out users quickly)
Email's persistence is its superpower. A push notification disappears after a swipe. An in-app message vanishes when the user navigates away. An email stays in the inbox.
The Framework: Urgency × Complexity
Map your messages on two axes:
High urgency, low complexity → Push notification. "Your trial ends tomorrow" or "Flash sale: 50% off today only."
Low urgency, high complexity → Email. A detailed product update, a monthly affiliate performance report, or an onboarding guide.
Any urgency, contextual to current app use → In-app message. Feature tips, upgrade prompts, and satisfaction-triggered referral invitations.
High urgency, high complexity → Push notification to alert, linking to either an in-app message or email for details.
Channel Coordination
The best app communication strategies use all three channels together. A new feature announcement might include:
- An email to all users with full details
- An in-app message for users who open the app in the following week
- A push notification only for users who did not open the email or the app within 3 days
This cascading approach maximises reach without bombarding any single user across all channels simultaneously.
Track which channels each user engages with and lean toward their preferred channel over time. Some users read every email but dismiss push notifications. Others never check email but respond to push. Let user behaviour guide your channel mix.