- Links to poor quality content: I found once a page that really performed badly. I discovered that one external link on this page linked to a login page on another website. That’s why I think it is important to add a nofollow when linking to the login page.
- Affiliate links: SInce you earn money in exchange of an affiliate link, affiliate links that pass Google juice are forbidden by the Google webmaster guidelines. You should add a nofollow to affiliate links.
- Links to
bad neighborhood: This is when you link your website to a website that has been penalized by Google. Your page or maybe your website traffic can drop because of an external link. That’s why Google suggests adding a nofollow to the signatures of forum members, links inside comments, links inside guestbooks. - Sneaky redirect: That’s when you hide a link behind another link using Javascript. Usually, the user will click on a link to reach a page and after 2 seconds, this user will be redirected to another page that
googleBot can’t see. - Paid links: This is when you sell links to 3rd parties.