If you don't mind sharing, how much do you get through those affiliate programs compared to advertising?
Also, would you consider providing some kind of paid model in addition to ads? I use DDG dozens of times per day as my primary search engine; I would happily pay for it. I realize that model doesn't scale to the entire world, as only a fraction of people will pay, but do you have some way for people who like what you're doing to pay you a modest amount, with as little friction as Patreon and similar?
We haven't disclosed it, but advertising is the bulk.
The problem with paid is three-fold. We're a for-profit company so don't want to come off as taking donations like a non-profit. Second, we don't want to collect personal information. So we could do something like bitcoin but that isn't exactly low-friction :). Third, it is promoting that it exists. We have a hard problem getting the word out about anything not on the SERP and we wouldn't want to put it there.
Regarding personal information, I have no problem providing payment information, as long as that isn't tied to accounts/searches/etc. (A separate service, similar to Patreon, seems ideal.) But I do realize that the number of people willing to pay you may not justify the work needed to set something up.
I do understand your concern about not wanting to appear to take donations, though. I just wish I had some way to pay you for your service that doesn't involve viewing or clicking on ads.
We really suggest people who want to help to just help spreading DuckDuckGo, which is honestly our biggest problem (not money): https://duckduckgo.com/spread
Also, would you consider providing some kind of paid model in addition to ads? I use DDG dozens of times per day as my primary search engine; I would happily pay for it. I realize that model doesn't scale to the entire world, as only a fraction of people will pay, but do you have some way for people who like what you're doing to pay you a modest amount, with as little friction as Patreon and similar?