Google’s Martin Splitt answered a question about whether internal nofollow links and noindex meta robots directives send the wrong signal to Google that the website is low quality.
Nofollow Link Attribute
The nofollow link attribute came about as a standard created by Google, Yahoo and Microsoft that publishers can use to signal that a link can’t be trusted (such as links in user generated content) or for paid links. The idea is that the links can’t be trusted or used for ranking purposes or for whatever reason.
SEOs discovered that PageRank didn’t flow through links that had the nofollow attribute so naturally the self-identified “white hat” SEOs tried gaming Google by adding nofollow links to their privacy and about us pages in order to funnel the maximum amount of PageRank to the pages that mattered. This practice was called PageRank Sculpting and it shows that adding nofollows to internal links is longtime practice and that it’s never been a problem before.
For the record, PageRank sculpting doesn’t work because, in a highly simplified explanation, Google essentially counts the amount of links on a page, including links with nofollows and divides the amount of PageRank that flows as if all the links counted. That’s how it was explained many years ago and that may have changed over the years, we don’t really know.
Noindex Robots Meta tag
The noindex robots meta tag is a directive that crawlers like Googlebot are required to obey. It allows a publisher a way to block crawling at the page level.
There is nothing about the noindex value of the meta element that indicates whether the page is untrustworthy or anything like that. It’s just a way to control crawlers.
Google’s Martin Splitt narrated the question:
“Can a lot of internal links with nofollow tags or many pages with noindex tags signal to Google that the site has many low-quality pages?”
Martin answered:
