DDG does run ads just like Bing and Google, so it's just a way for Bing to get more search ad inventory out there. Once upon a time there were other sites that

DDG does run ads just like Bing and Google, so it's just a way for Bing to get more search ad inventory out there. Once upon a time there were other sites that did the same thing with Google, but eventually Google decided they didn't need third parties to drive search traffic.