Google PageRank Sculpting Revised
How Google PageRank Flows between Web Pages:
- A decay factor of 10-15% loss applies to each time PageRank (link juice) passes from one web page to another.
rel=nofollowattribute is a method to indicate no PageRank (link juice) should be passed through to the web page being linked to from your web page.
The nofollow attribute is just a mechanism that gives webmasters the ability to modify PageRank flow at link-level granularity. Plenty of other mechanisms would also work (e.g. a link through a page that is robot.txt’ed out), but nofollow on individual links is simpler for some folks to use. There’s no stigma to using nofollow, even on your own internal links; for Google, nofollow’ed links are dropped out of our link graph; we don’t even use such links for discovery. By the way, the nofollow meta tag does that same thing, but at a page level.
Let’s revise Google PageRank Sculpting. PageRank Sculpting can be used as:
- “Siloing” – Only pass link juice to web pages on your site with the same theme to improve ranking for keywords and keyword groups, that are both general and targeted keyword phrases.
- Signals to GoogleBot crawl prioritization for your site’s web pages.
Changes to Nofollow Attribute, PageRank Sculpting
Matt Cutts explains how nofollow attribute works after Google made algorithmic change to how Nofollow attribute passes PageRank (link juice) between web pages:
- For example, your web page has 10 PageRank points (from inbound links pointing to the web page). You set up 5 links pointing to other web pages on your site and 5 outbound links to other websites. You blocked PageRank from passing through the 5 outbound links with nofollow attribute.
- Before Google’s algorithm change, you could pass 2 points to each of the 5 web pages of your site, with a total of 10 PageRank points staying on your own site’s web pages.
- After Google’s algorithm change in 2008, you could only pass 1 point to each of the 5 web pages of your site, with a total 5 PageRank points staying on your own site’s web pages. The other 5 points are lost.
- Links to sites that you do not trust
- Links to sites that you do not want to vouch for
- Paid links
As Webmasters, you should not add “nofollow” to all outbound links on your site.
Other SEO Techniques
Webmasters should avoid keyword stuffing and consider using other SEO techniques before applying nofollow attribute to websites.
- Google +1 Button Setup, Google +1 on SEO, Adwords
- Google SEO beginners guide update
- Google, Yahoo and Bing search algorithms
- Google SEO for beginners
- SEO geo-targeting