Web directories and link directories
Tips to avoid a penalty
Audit backlinks from web directories and link directories frequently.
Monitor the amount of traffic these directories and listings bring to your site and their overall performance on the SERPs.
If a link generates quality referral traffic, ask the webmaster of the site where the link is located and set rel=”nofollow” or rel=”sponsored” attributes.
Avoid overusing this link building strategy and only add links to high quality sites.
Remove these links.
Disavow any links you can't remove.
6. Pure spam
Frequency of cases : 14%
Google is very sensitive when it comes to purely australia phone number data spammy links; it has absolutely no tolerance for this type of search engine optimization efforts.
Keyword stuffing.
Misleading redirects .
Links that are not relevant to the content or topic of the page.