Datafinder - Least expensive, pretty good results. With bulk requests I think an email is around $0.075 a hit. I use them daily and I like them. Only one I've found that had my personal email address. Source: about 2 years ago

Good question. I have yet to find a consistently good source for email addresses that are public. I use datafinder to get email addresses once I have the individuals name and state but you do have to pay per email found. While the email quality is better than any other I have found, it's still just going to be okay. Source: over 2 years ago

Alternatively, you can research the address using websites and data sites like “datafinder” and others - try https://datafinder.com/. Source: about 3 years ago

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