Page Rank (named after Larry Page) is a link analysis algorithm used by Google that measures how many links point to a website or page, and more importantly the quality or importance of the sites that provide those links. It uses a numerical scale, with 0 being the least important and 10 being the most important. In an attempt to “cheat the system", some website owners have tried to purchase links back to their website hoping for a higher Page Rank. However, those low quality links can have a negative impact and result in a lower Google Page Rank. In addition, a website may be penalized or blocked from search results, giving priority to websites and web pages that have quality backlinks and content that is valuable to humans.
The process of harvesting search engine result pages data is usually called "search engine scraping" or in a general form "web crawling" and generates the data SEO related companies need to evaluate website competitive organic and sponsored rankings. This data can be used to track the position of websites and show the effectiveness of SEO as well as keywords that may need more SEO investment to rank higher.

Inbound links (links into the site from the outside) are one way to increase a site’s total PageRank. The other is to add more pages. Where the links come from doesn’t matter. Google recognizes that a webmaster has no control over other sites linking into a site, and so sites are not penalized because of where the links come from. There is an exception to this rule but it is rare and doesn’t concern this article. It isn’t something that a webmaster can accidentally do.

AdWords Customer Match lets you target customers based on an initial list of e-mail addresses. Upload your list and you do things like serving different ads or bidding a different amount based on a shopper’s lifecycle stage. Serve one ad to an existing customer. Serve another to a subscriber. And so on. Facebook offers a similar tool, but AdWords was the first appearance of e-mail-driven customer matching in pay per click search.
PageRank is a link analysis algorithm and it assigns a numerical weighting to each element of a hyperlinked set of documents, such as the World Wide Web, with the purpose of "measuring" its relative importance within the set. The algorithm may be applied to any collection of entities with reciprocal quotations and references. The numerical weight that it assigns to any given element E is referred to as the PageRank of E and denoted by {\displaystyle PR(E).} Other factors like Author Rank can contribute to the importance of an entity.
In the 2000s, with more and more Internet users and the birth of iPhone, customers started searching products and making decisions about their needs online first, instead of consulting a salesperson, which created a new problem for the marketing department of a company. In addition, a survey in 2000 in the United Kingdom found that most retailers had not registered their own domain address.[12]These problems made marketers find the digital ways for market development.
The green ratings bars are a measure of the importance Google’s assessment of the importance of a web page, as determined by Google’s patented PageRank technology and other factors. These PageRank bars tell you at a glance whether other people on the web consider Google considers a page to be a high-quality site worth checking out. Google itself does not evaluate or endorse websites. Rather, we measure what others on the web feel is important enough to deserve a link. And because Google does not accept payment for placement within our results, the information you see when you conduct a search is based on totally objective criteria.
Size: (green) The size of the text portion of the web page. It is omitted for sites not yet indexed. In the screen shot, “5k” means that the text portion of the web page is 5 kilobytes. One kilobyte is 1,024 (210) bytes. One byte typically holds one character. In general, the average size of a word is six characters. So each 1k of text is about 170 words. A page containing 5K characters thus is about 850 words long.
Early versions of search algorithms relied on webmaster-provided information such as the keyword meta tag or index files in engines like ALIWEB. Meta tags provide a guide to each page's content. Using metadata to index pages was found to be less than reliable, however, because the webmaster's choice of keywords in the meta tag could potentially be an inaccurate representation of the site's actual content. Inaccurate, incomplete, and inconsistent data in meta tags could and did cause pages to rank for irrelevant searches.[10][dubious – discuss] Web content providers also manipulated some attributes within the HTML source of a page in an attempt to rank well in search engines.[11] By 1997, search engine designers recognized that webmasters were making efforts to rank well in their search engine, and that some webmasters were even manipulating their rankings in search results by stuffing pages with excessive or irrelevant keywords. Early search engines, such as Altavista and Infoseek, adjusted their algorithms to prevent webmasters from manipulating rankings.[12]