Contextual advertising on commercial sites and SEO?

Question

Search Engine Optimization

Is there reliable information that prevents the promotion of a commercial site by the presence of advertising on it?

Answer 1

If a site providing commercial services advertises other people's identical services on its site, this is a sure signal that it may be worth ranking lower than others.
EMNIP something on this topic was in the rules of YAN/Adsense (for example).

Answer 2

Aggressive, shocking and emotional advertising - downgrading in Yandex.
The entire first screen is clogged with ads - possibly a downgrade to Google.
The rest does not affect 100%

Answer 3

If advertising worsens the perception of basic information, then it can interfere.
In general, if you do not go too far, Yandex and Google themselves are primarily interested in advertising on websites. They also give you a recommendation on how best to place it.