There is an interesting new thread at the Black Hat World forums around a site that saw its rankings drop recently, and them trying to figure out if it is related to the acquisition of PBN based links from about four months ago.
The SEO said:
Added a link from a large PBN, every single one of my tracked keywords have dropped off the top 100 rankings in multiple countries.
Site is 4 months old.
Is this normal? I've experienced G Dance before where it drops 20-30 positions, but all of them have dropped off.
It's a BH site so it's not in Webmasters
The SEOs there then start digging into the ratio of the types of links the site has, which he replied to as:
- 55% URL (no http)
- 18% HTTPS + http URL
- and 2% (1 link) for each KW according to Ahrefs. As well as some random terms like "Here", "click here", "find out more"...etc
In any event, it is interesting reading some of these threads.
Forum discussion at Black Hat World.