> Ads are always separate and clearly labeled.
Indeed. Let's look at Google's launch of Adwords in October 2000:
> Google’s quick-loading AdWords text ads appear to the right of the Google search results and are highlighted as sponsored links, clearly separate from the search results.
https://googlepress.blogspot.com/2000/10/google-launches-sel...
Things evolved from there, and that's likely here, as well, I think.