For me, success is building stable, secure apps that have utility and relevance in my user's lives while also respecting their privacy!
I believe if we do the above then, people will buy our reasonably priced products. I'm a capitalist, and yes, we charge for some of our services, while others are free. By free, I don't mean that 'surreptitious free' confronting one daily with the promise of 'seamless integration' of your data into the app. Of course, even though they are not charging you upfront for using the app, the value of your data and how they can use it puts you at a significant loss.
When we say an app or service is free, it's just that FREE!
Our stance on free and privacy is good; we don't rifle through your data pockets to make cash on the down-low; we do, though, collect IP addresses and unique keys assigned to each of our apps that connect to our servers. Our privacy policy explains it all.