This applies to Plausable as well as to BeamAnalytics: You claim that the data of your users "belongs to them" and only to them.
Question: "How can any of your users verify that you're not selling their data?"
There's no way other than believing your word. And you have access to the DB. Therefore, given that your claims and the ones of Plausable, can't actually be verified by their users, any time, how is your service different from Google Analytics than? At least with Google Analytics one knows that there's no privacy.
In your case the user doesn't know it with certanty because he can't verify it, but he assumes that everything is performed correctly and privacy-friendly -- by taking your, and the owners of Plausible, word for it. It's based mostly on believe, that is.
Question: "How can any of your users verify that you're not selling their data?"
There's no way other than believing your word. And you have access to the DB. Therefore, given that your claims and the ones of Plausable, can't actually be verified by their users, any time, how is your service different from Google Analytics than? At least with Google Analytics one knows that there's no privacy.
In your case the user doesn't know it with certanty because he can't verify it, but he assumes that everything is performed correctly and privacy-friendly -- by taking your, and the owners of Plausible, word for it. It's based mostly on believe, that is.