Here are some of the key points on the topic:

• Domain Trust/Authority " Until the Florida update (November of 2003), not many SEOs took this factor seriously. Today, it has become one of the most dominant factors in the success of rankings at Google. However, it doesn't mean that exact-match domain names and lots of anchor text from diverse root domains can't still overwhelm the occasional page from Wikipedia, Amazon or the BBC, but the preferential treatment has reached new heights.
  
  In the past few days, you may have noticed authority sites like Technorati has started re-ranking their tag pages on every SERP they target. Even the Google's "Brand" or "Vince" update also emphasize this point.
• Anchor Text in External Links " It is considered to be a very powerful ranking tactic. But, over the years it has lost its importance as it used to carry before 2004. At present, anchor text is considered to be as PageRank. Since it has a dominance in the algorithm.
• On-Page Keyword Usage " Earlier, Google was susceptible for keyword stuffing, which led to the myth of keyword density as a ranking factor. Although, it has not lost all its power since it's still considered as an essential element.
• Raw PageRank / Link Juice " In the olden days, PageRank used to hold a very important place. Getting a few high PageRank links was very simple, just needed a little ranking manipulation. However, by the year 2003, PageRank started declining as a ranking factor and still continues to decline. Though, it can still make some certain difference, for inclusion in the index and comparison against duplicates & scrapers.

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