Ecosia shows ads in its SERPs, which it calls EcoAds. In order to show ads and search results it has partnered with Bing (we love Bing!).
Through this model, Bing shares a portion of the revenue generated by these ads.
Ever been innocuously browsing the web for your next pair of shoes, before leaving the retail site to browse your social media, only to find the shoes have followed you in an advertisement – reminding you you’ve forgotten them? That’s dynamic remarketing.