Why it matters to a buyer
Links remain one of the ways search engines judge which of two similar pages to trust, so competitive queries are hard to win without them. But the quality gap between links is enormous, and bought links can lead to a manual action that removes rankings. For a buyer, the questions to ask of any link-building offer are where the links come from, whether they are paid placements, and whether the sites have real readers of their own.
How it is measured or applied
Links are earned by publishing something other sites want to reference, such as original data, tools or expert commentary, and by outreach, digital PR and relationships with relevant publications. Links that are paid or sponsored should carry the sponsored or nofollow attribute. Backlink profiles are measured with Search Console's links report and third-party tools that estimate referring domains and link quality. Useful reporting counts new linking domains, their relevance to your market, and the rankings of the pages they point to, rather than a raw link count.
Sources
- Spam policies for Google web search, Google Search Central
