The problem of scale for profitability from ads is certainly there. You could look to use something like admob to start with to make some money back (although the earnings likely will not cover with cost of marketing, without scale). Source: over 1 year ago

1. AdMob Google is the No 1 player in the mobile advertising market. It was already the largest online advertising company when it acquired AdMob. AdMob makes earning revenue easy with in-app ads, actionable insights, and powerful, easy-to-use tools that grow mobile apps. - Source: dev.to / almost 2 years ago

Use online services, such as Google AdMob, for filtering and sorting in-app ads. Source: over 2 years ago

There are different ways to monetize with your Flutter app. You can make users pay to download it, you can have in-app purchase plans, you can let users subscribe using recurring payments to use all the features, or you can show ads to your users. In this article, Dhruv Nakum teaches you how to integrate AdMob into your app. - Source: dev.to / over 2 years ago

I would highly recommend Scopio too. That way you will be paying the contributors for their photos. I'm so fed up by this monopolization of stock images. Pexels and pixabay will provably be the next corps to get acquired by getty. Source: about 3 years ago

Scopio is a great alternative! It offers a wide selection of authentic images and the contributor will be paid for every download. Check it out here https://scop.io/. Source: about 3 years ago