I've been using duckduckgo as my main search engine for about 2 years but I never recommend it to anybody. It just feels like a homeopathic remedy to me. What's

I've been using duckduckgo as my main search engine for about 2 years but I never recommend it to anybody. It just feels like a homeopathic remedy to me. What's the business model? I don't allow them to show me ads and they don't allow me to pay for the service. I just can't imagine how that can scale. Search engines are such an important tool that I would be more than willing to pay $10 a month for a good quality one with strong commitment to privacy and maybe additional premium features.