I've seen pages where the Text Ads have the same Style as the overall page. The only thing that sets the Ad apart is a small grey text 'Ads' or the like.

I've may have seen far more of such pages. But obviously i can't tell since they're near-impossible to spot the Ads.

The trend is keeping things "by the book" from search engines point of view, And manipulate humans in subtle ways by confusing contents and ads.