Unnatural Links Can Hurt a Site Regardless of Algorithm Updates
If you believe your site is suffering from poor link-building schemes, John recommends focusing on removing these unnatural links, regardless of any algorithmic updates. This can be done in a number of ways, including using the disavow file or removing links from the source site.
Disallowed Pages With Backlinks Can be Indexed by Google
Pages blocked by robots.txt cannot be crawled by Googlebot. However, if they a disallowed page has links pointing to it Google can determine it is worth being indexed despite not being able to crawl the page.
Web Spam Team Can Issue Targeted Manual Actions Against Pages With Unnatural Linking
The Web Spam team can take targeted manual action against websites with unnatural linking by choosing to disregard links to individual or small groups of pages.
Value of Backlinks Changes Over Time as Sites Grow in Size & Adds More Links
Backlinks don’t lose their value directly because of their age, but PageRank is distributed more broadly over time as the linking site publishes pages and increases the volume of links.
Google Doesn’t Place Fixed Weight on Backlinks in its Algorithms
Google doesn’t place a fixed weight on backlinks in its algorithms, it varies from case to case. For example, a new article may rank well for a trending topic but have few links because it is so fresh.
Rather Than Redirecting Temporary Pages, Encourage Users to Link to More Permanent Pages
If you have a page that will only be live for a short amount of time, instead of trying to consolidate link equity through redirects, John recommends encouraging users to link to more permanent pages on your site like category pages.
Anchor Text Helps Google Understand Topic of Target Page
The anchor text in a link helps Google understand the broader topic of the target page.
Google Ignores Links From Press Releases
Links from press releases are generally ignored because Google knows that companies publish these themselves. John doesn’t recommend relying on links from press releases as part of a link building strategy.
Links to Different Language Sites Provide Same Value as Same Language Links
Links to a different language site provide the same value as links to same language sites.