Ask: Get existing Duolingo users back on the app 
Approach: Take Duo the bird off the app

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After becoming the most bullied mascot on the internet due to relentless nagging to complete daily lessons, Duo decides he has had enough. With one final Duolingo notification, Duo resigns. 
A disgruntled Duo proceeds to deface all current Duolingo ads.
Meanwhile, back at Duolingo headquarters, the team needs a replacement to send out the daily reminders. Enter Brad. The intern who is far more annoying than Duo. 
While Brad takes the stage as new annoying notifier, we’ll share what’s happening back at Duolingo HQ via TikTok

In the absence of Duo, and the ensuing chaos of Brad’s notifications, the intenet will campaign for Duo’s return, and Duo will decide to come back.