For Germany, below the prices it says "some links may be sponsored", but it does not mark which ones. Is that even legal? Also there seem to be very few shops, are maybe all the links sponsored? Also idealo.de finds lower prices.
When I decided to put the text like that, I had looked at maybe 10-20 of the biggest price comparison websites across different countries because I of course want to make sure I respect all regulations that there are. I found that many of them don't even write anywhere that the links may be sponsored, and you have to go to the "about" page or similar to find this. I think that I actually go further than most of them when it comes to making it known that some links may be sponsored.
Now that you mention idealo, there seems to be no mention at all on a product page that they are paid by the stores, you have to click the "rank" link in the footer to be brought to a page https://www.idealo.de/aktion/ranking where they write this.
