I am sorry but you already had a fan base. So you already had 1000s of users. And you told them before launching this app is coming. How is this not marketing?

This is why I don't like to read and believe things on internet. You leveraged your prior advertising. And the rest of the things you mentioned was basically, build a great product. Everyone here knows that. But we have also heard so many times no product sells itself irrespective of how great.So I don't know what was the point of mentioning all those features etc

You also used SEO tactics to get people find your app. That is also classic internet marketing