Citations and Co-Citations for Local SEO

The pagerank algorithm was largely gamed because all it required was a black-hat SEO person building keyword-rich links back to a site. Over time, regardless of where the links were built, the site would rise in rank. Google knew that their search engine results were being gamed and subsequently strengthened their algorithms to pick up other quality queues. The quality of the linking site and relevance of the content their played a role as well