This is the exact model that I use on RadioReference.com. We have an API that exposes our entire radio database to end users, but they must be premium subscrib

This is the exact model that I use on RadioReference.com. We have an API that exposes our entire radio database to end users, but they must be premium subscribers to access the data through the API. This spurred the development of tons of radio programming and other apps in the ecosystem. It's literally a win-win for all of us. It's easy to detect "abuse" or "commercial use" and we contact those users and license them accordingly for such use cases. We also went one step further and completely eliminated advertising on RadioReference.com. Given the user base is very niche and highly technical, the goodwill alone we got from that move gave us a sizable increase in premium subscription revenue. Plus, the quality, of Internet advertising has become so poor it's barely worth opening the space up to advertisers.