Alternative to notification ads

Hi

I am the author and developer of https://play.google.com/store/apps/details?id=com.brik6.busboy - It’s an app to get bus information by shaking your phone without opening the app (For london buses). The information is displayed as a notification.

As you can tell, users would rarely be opening the app. And displaying notificaiton ads is against Google’s policy.

My question is, other than a freemium model with some locked features, any suggestions on how to monetise the app?

Thank you!

How about in the notification area, after the shake, you could add some extra content ( for example: Maybe this route is better for you etc etc) which will be displayed in the main menu of the app when the user clicks on it.
I dont know what it could be exactly, you know your app better. But it is obvious you need to make rearrangements to make users open the app.

Thanks Anteos. It’s a good suggestion but the whole idea is to make the use case very easy for users by not having to open or interact with the app.