The first update for 2005 was the nofollow attribute in January. The function was created through collaboration between Google, Yahoo, and Microsoft to battle against web spam by enhancing how search engines identify spam links.
This new indexing command aimed to reduce the link and comment spam that affects many websites particularly high-performing blogs. The nofollow attribute is a value assigned to a link and anchor text that acts as a flag to search bots about how the hyperlink shouldn’t affect the ranking of the target in its index since the owner has explicitly not vetted it. It’s a way to signal Google that someone else added the link to the site, not the blogger.
While it may not have been the regular algorithm update, the use of the nofollow attribute did have a significant effect on the link graph. Bloggers, forum operators, and websites that allowed guest posting suffered considerable losses in their ranking when people exploited the system by spamming them with links.
Blog comment spam was a favorite black hat tactic in Google’s early days because it was an easy tool that helped spammy sites rank well on the search engines. This time, they can easily add this value as a default for hyperlinks posted in the comments section and their site’s reputation is protected.
A nofollow attribute for a link signals to Google that:
There’s no follow through to that particular page.
It shouldn’t count the link in measuring PageRank link popularity scores.
It shouldn’t include the anchor text in identifying what search terms the target page is relevant for.
It’s crucial to understand that a nofollow attribute doesn’t signify that you’re flagging a site or page as untrustworthy. It merely denotes the fact that you’re informing Google that you don’t own the link and don’t explicitly approve of its inclusion in your content.
Some people still practice comment spamming, especially in blogs. It’s essential that you protect your site’s reputation by making nofollow a default in the comments section, guest posts, or parts that involves visitor participation.
Inbound links from blog comments, social media posts, forums, news sites, widgets, and press releases are typically nofollow today. Popular websites that use this attribute on outbound links include YouTube, Wikipedia, Reddit, Medium, and Quora.
Nonetheless, a nofollow link still has SEO value because: