I guess I'll have to earn trust the long, hard way :

* clear policies on how user data is handled

* explicit commitment to never sell user data to third parties

* transparency about any specific concerns users might have

* no dark patterns to trick users or website owners

* a track record of good decision making and staying true to the commitment to privacy

And for people who find me through forums (including HN) or via my blog, I think my privacy + no bullsh*t leanings are pretty clear.

Since I'm solo and bootstrapped, I don't know what options I have regarding independent verification of my claims, but if I get to a point where I can explore such options, I'm all for third party verification of my claims.