Ask HN: What makes you loose credibility on a web resource?
What makes you close a site immediately (like a GitHub project, a landing page, a HN posts, a blog post)?
Low contrast between text and background, bonus points if the font is really thin.
Highlighting text does anything other than highlighting text (e.g. opening a menu to share quote on twitter)
Scrollbar highjacking
Clicking on background takes you away from the article (TechCrunch used to do this)
Scrolling down takes you to another article (some news sites do this)
(2) Pop-over windows (e.g. sign up to our email newsletter)
(3) Ads out of control; not "ads cover content" but "ads cover ads". Many sites like anandtech are designed now so that the pages jitter on mobile in such a way that you try to scroll and somehow an ad gets positioned under your finger and KA-CHING!
(4) Taboolah, Outbrain, anything like that.
(5) "Hiring is Broken", "Does your API need a content marketing strategy?" and other fake memes that are promoted on a pay-for-play basis by Triplebyte, Mulesoft and other information polluters.