1. Provide your service with the option of collecting nearly zero or precisely zero data about customers if they so choose. In order to do this, it may be necessary to provide your services as open source software they can operate themselves on hosts they own or lease.
2. Adopt a comprehensive privacy-respecting mission statement analogous to the portions of the Mozilla manifesto [1] pertaining to privacy.
3. Provide full transparency about when, how, and in what measure data is collected about users who have not opted out via #1 above.
4. Ensure that your revenue streams are firewalled from user data. Never allow user data to be considered a potential source of revenue.
5. To the extent feasible under the law, provide transparency about revenue and finances. Provide evidence that the business is healthy thanks to voluntary exchange of money from principal users for products or services, and not exchanges that are involuntary for users.
Very similar to the game theory experiment of having a piece of cake to cut: one person gets to cut, the other person gets to pick the piece they want. You have to handcuff yourself to doing the right thing. Your decisions about "being evil" then become easy; you simply can't pick those paths knowing you've locked in the consequences.
But, that doesn't account for Amazon who have become (or were always?) evil in their own special ways.
Obviously that's a poor risk assessment: of course it's easy to make the annoying-bug-beneficial choice when it doesn't cost much. The actual test is what happens on a very bad day when you're exhausted and worried about other problems. Most people eventually end up caving and "cheating" on their diet, simply because we're terrible at judging risks and overestimate our ability to resist temptation when it isn't actually being tested.
The solution to this problem is to have the humility to admit our weaknesses in assessing risks and how easy it can be to overestimate our own abilities. From that point of views, prudence suggests a good idea might be using the benefits available on good days to prepare for the bad days and moments of weakness. Don't allow the temptation into the house so succumbing to temptation isn't possible or involves a much higher cost.
Words that promise that you won't fall to temptation are hard to enforce on yourself if the company has as bad quarter/year and finances are tight. Instead of words, the way for as company to distinguish themselves from the mostly-empty promises of the past is to publicly remove your own ability to make the wrong choice. If your hands are tied by a Ulysses Pact[2], it doesn't matter if someone offers to drive a dump truck full of money to your house if you sell out your users[3]: the decision has already been made and you no longer have that power.
[1] https://youtu.be/Yth7O6yeZRE?t=18765 (Doctorow's talk starts at 5:12:45)
What words or actions could you invoke that would allow it to be distinguished from what some previously friendly sounding companies said or did during their ascent?