Google and Bing are the only ones that matter and you can’t compete with Google by paying them for their search results.
Yandex is Russian and has pretty poor results. And you’d be naive to think that those of us concerned about privacy would ever touch something built on top of it.
In other words there aren’t paid search engines that DuckDuckGo could turn to. Unless they build their own crawler, the only game in town is Bing.
There is no difference in terms of building something on top of Bing or Yandex as your private data never touches their servers. All they get is anonymized stream of queries, in this case from DuckDuckGo.
And yes you can compete with Google (for a certain target group) by paying them for their search results. Results are just a distribution channel, it is what you do with them that matters. For example Google and DuckDuckGo both choose to show you ads and affiliate links but that is hardly the only option.
Yandex is Russian and has pretty poor results. And you’d be naive to think that those of us concerned about privacy would ever touch something built on top of it.
In other words there aren’t paid search engines that DuckDuckGo could turn to. Unless they build their own crawler, the only game in town is Bing.