Unity开发者求助：能否向已卸载Android应用的用户发送Push通知？

Hey fellow Unity dev! Let's break down your question clearly: you can't send direct push notifications (like you do with OneSignal) to users who've uninstalled your Android app—push tokens are tied to the installed app instance, and once the app's gone, the system invalidates that token, so no push service can target those devices anymore.

That said, there are legitimate, actionable ways to reach these uninstalled users:

• Leverage collected contact information：If your app gathered user emails, phone numbers, or other contact details during sign-up/usage (with explicit user consent, of course), you can use email marketing or SMS campaigns to send recall messages. You'd export these contacts from your user database or OneSignal's user records (if you stored them there) and use a compliant marketing tool to deliver your message.
• Platform re-engagement ads：Services like Google Ads' app re-marketing let you upload lists of user device IDs (pulled from your app's user data or OneSignal) to target users who've uninstalled your app. These ads will show up across Google's ecosystem (Search, YouTube, Play Store) and can drive users back to download your app again.
• App store targeted messages (limited access)：Some app stores offer restricted tools to send recall messages to uninstalled users, but these usually require meeting specific eligibility criteria and adhering to strict platform policies. It's worth checking your target app store's developer documentation for details, but this isn't a universal solution.

Important note: Make sure all these methods comply with privacy regulations like GDPR or CCPA—you must have explicit user consent to contact them through any channel beyond in-app pushes.

内容的提问来源于stack exchange，提问作者M Yasir