Years ago, I started referring to search results as recommendations, seeing how they’ve been starting to look more and more like that part of a page at Amazon that says “people who viewed this book also looked at these books.”
When someone searches at a search engine, one of the things they look for in the search results they receive are trustworthy pages (or recommendations) that look (and are) legitimate. How does a search engine deliver pages that are trustworthy?
One way to do that might be to try to boost pages in search results that the search engine feels are more trustworthy – and Google developed a version of Trust Rank to do that with. The inventor of Google’s Trust Rank (which differs from the version that Yahoo invented) is Ramanathan Guha.