> DDG are without question data brokers, and commercial websites that make promises like DDG does will not survive for long if they actually keep them.
I'm not convinced that this is a law of nature, but it does seem to have some truth in it. I pay ~$5/month for services like Feedly and Evernote. I'd be willing to do the same for a high quality search engine that does not make me the product.
Search is probably the most likely counterexample of your rule. They can sell ads based on search terms instead of user profiles. This might be leaving some profit on the table, but might not.
They can generate artificial scarcity by preventing the search query stream from being joined to user profiles by third parties.
If they end up with a well-educated, affluent userbase (likely, given their selling point), they can charge a huge premium for that scarcity.
This trick is much older than the internet itself.
I'm not convinced anymore that paying for a service doesn't make you the product. Look at Windows 10, Android devices, heck almost anything. Collecting and selling user data seems almost inevitable if law makers don't drop Thors hammer.
Unfortunately paying doesn't alone incentivize data privacy, when those same companies you're paying realize they can also increase profits my monetizing your data or everyone's data in aggregate.
I'm not convinced that this is a law of nature, but it does seem to have some truth in it. I pay ~$5/month for services like Feedly and Evernote. I'd be willing to do the same for a high quality search engine that does not make me the product.