Idealo allows displaying offers for a product, but also ads.
Additionally, Netrivals/NetMonitor will suggest or automatically connect you to offers but never to ads.
The URLs for offers are structured like this:
https://www.idealo.de/preisvergleich/OffersOfProduct/202998400_-recon-schwarz-macna.html
Whereas the URLs for ads are structured like this:
https://www.idealo.de/preisvergleich/ProductCategory/18398.html?q=04063769342947
It is possible to create manual connections or passive connections to ad-type URLs. However, please note that all search results by EAN will be considered for the buy box calculation.