This week in Business Intelligence class, we learned about Google and how it decides on which pages to display first. This is a very interesting topic since there are not many people that will continue past the first page when they are searching something. Due to this fact, if you are a website owner, it is very important to have your page on the initial result set.

According to Google, page rank is defined as follows:

"PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page’s value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. But, Google looks at considerably more than the sheer volume of votes, or links a page receives; for example, it also analyzes the page that casts the vote. Votes cast by pages that are themselves “important” weigh more heavily and help to make other pages “important.” Using these and other factors, Google provides its views on pages’ relative importance."
Source: http://searchengineland.com/what-is-google-pagerank-a-guide-for-searchers-webmasters-11068


Google has a page rank website that will rank any website that you enter. Since page ranking is very important for websites, the website owners will try to increase their page rank anyway possible. For example, websites may add keywords in white text to try to have higher page views from Google when keywords are searched. There is a war going on with websites in order to remain on the first page of results from a Google Search.


In addition to page ranking, Google uses Ad Rank to rank advertisements that will be shown based on search criteria. The ad rank score is calculated based on two factors, which are Cost per click, and the Quality score. It is more important to have a strong quality score than paying a high cost per click for the advertisers since they want to earn profits. The quality score is measured based on relevance to the search topic. 


Source: http://support.google.com/adwords/bin/answer.py?hl=en&answer=1722122&from=6111&rd=1


Here is a video that describes the Quality Score in depth: