[boogies]

As others have mentioned, they run ads — based on the search query of the page they appear on. They also (not unlike Brave) participate in affiliate programs. They get referral commissions when they funnel people to Amazon or eBay, whether through their shopping carousels or through !bangs.

> use them anyway because they at least claim to be private

Me too, at least there's probably some chance they get sued if they’re as terrible as Google. But

> haven’t yet given me specific reason to doubt it

I do doubt they’re as private as they could be, because they act a lot like I imagine a honeypot does, hide their source code, and have had serious past privacy problems in other products (https://news.ycombinator.com/item?id=23708166 ‘We’re not collecting your info, our servers are receiving it but just trust us we just throw it away’).