Google’s Martin Splitt addressed whether using internal nofollow links and noindex meta robots tags might indicate to Google that a website is of low quality.
Nofollow Link Attribute
Google, Yahoo, and Microsoft developed the nofollow link tag, which publishers can use to indicate that a link is not trustworthy (e.g., links in user-generated material) or that the link is paid for. The concept is that the links are unreliable and should not be used for ranking or any other purpose.
When SEOs found that links with the nofollow property prevented PageRank from flowing via them, they immediately began to refer to these as “white hat” links. In an attempt to trick Google, SEOs tried adding nofollow links to their about us and privacy pages in an attempt to direct as much PageRank as possible to the important pages. This technique, known as “PageRank Sculpting,” demonstrates that adding nofollows to internal links has long been done and has never caused an issue.
In summary, Google basically counts the number of connections on a page—including links with nofollows—and divides the amount of PageRank that flows as if all the links counted. This is why PageRank sculpting is ineffective. That was the explanation given many years ago, and who knows if anything has altered since then.
Noindex Robots Meta Tag
Crawlers such as Googlebot must abide by the directive included in the no index robots meta tag. It gives publishers the ability to prevent crawling on individual pages.
Nothing in the meta element’s noindex value suggests that the page is unreliable or anything of the sort. It’s merely a method of managing 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:
“No, it doesn’t signal low-quality content to us, just that you have links you’re not willing to be associated with. That might have many reasons – you’re not sure where the link goes, because it is user-generated content (in which case consider using rel=ugc instead of rel=nofollow) or you don’t know what the site you’re linking to is going to do in a couple of years or so, so you mark them as rel=nofollow.”
Nofollow Is Not A Quality Signal
Martin affirmed that using the nofollow link attribute or the noindex robots meta tag does not appear to indicate any value judgment about “quality.” They have no bearing on Google’s assessments of the quality of a site and are OK when used on internal links or to stop crawling.