It shouldn’t be impossible, I think app owner gets a cut from “the network” the same way farmers do. (But see the topic linked at the bottom for some potential issues)
I think the owner pays when an app stores private data, but I think it’s best to verify (I think @Seneca asked this in one topic full of questions, but I don’t know where it is).
I don’t know if you noticed, David today said public and private PUT’s will cost the same: