Most people who used the Google Toolbar probably never went through the effort of enabling the PageRank meter, which Google offered as an incentive to web surfers, a way for them to understand the quality of pages encountered when browsing (and a way for Google to understand what people were viewing beyond Google itself). But one group was very inclined to make the effort: SEOs.
SEO may generate an adequate return on investment. However, search engines are not paid for organic search traffic, their algorithms change, and there are no guarantees of continued referrals. Due to this lack of guarantees and certainty, a business that relies heavily on search engine traffic can suffer major losses if the search engines stop sending visitors. Search engines can change their algorithms, impacting a website's placement, possibly resulting in a serious loss of traffic. According to Google's CEO, Eric Schmidt, in 2010, Google made over 500 algorithm changes – almost 1.5 per day. It is considered wise business practice for website operators to liberate themselves from dependence on search engine traffic. In addition to accessibility in terms of web crawlers (addressed above), user web accessibility has become increasingly important for SEO.
The numbers didn’t quite sit right with me because there didn’t seem to be enough juicy inbound links to the winning page. Then I noticed that two key links were missing from the 10 node chart with the PageRank metrics on it when compared to the previous chart without the metrics. The two missing links are the two coming from node 2 to node 1. Suddenly it all made sense again and it was obvious why that page won.