Why it matters to a buyer
Nofollow matters most to a buyer as a compliance issue: any link that is paid for, part of a sponsorship, or an affiliate placement is required by Google's guidelines to carry sponsored or nofollow, and skipping that is a form of the exact link scheme manual actions target. A buyer paying for placements or guest posts should confirm the specific attribute used, since a site that quietly drops the required tag to make a paid link look more valuable is asking its client to share the risk.
How it is measured or applied
The attribute is added directly to the anchor tag, rel="nofollow" for a general case, rel="sponsored" specifically for paid or affiliate links, and rel="ugc" for links inside comments or forum posts a site does not fully control. Google has said it treats these as hints rather than absolute rules, and may still choose to crawl and use a nofollowed link in some contexts. It is checked by inspecting a page's outbound link attributes directly in its HTML or with a browser extension, particularly on comment sections, guest posts and any paid placement.
Sources
- Qualify your outbound links to Google, Google Search Central
