The PageRank algorithm outputs a probability distribution used to represent the likelihood that a person randomly clicking on links will arrive at any particular page. PageRank can be calculated for collections of documents of any size. It is assumed in several research papers that the distribution is evenly divided among all documents in the collection at the beginning of the computational process. The PageRank computations require several passes, called “iterations”, through the collection to adjust approximate PageRank values to more closely reflect the theoretical true value. Cartoon illustrating the basic principle of PageRank. The size of each face is proportional to the total size of the other faces which are pointing to it.[/caption]
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.
To avoid undesirable content in the search indexes, webmasters can instruct spiders not to crawl certain files or directories through the standard robots.txt file in the root directory of the domain. Additionally, a page can be explicitly excluded from a search engine's database by using a meta tag specific to robots (usually ). When a search engine visits a site, the robots.txt located in the root directory is the first file crawled. The robots.txt file is then parsed and will instruct the robot as to which pages are not to be crawled. As a search engine crawler may keep a cached copy of this file, it may on occasion crawl pages a webmaster does not wish crawled. Pages typically prevented from being crawled include login specific pages such as shopping carts and user-specific content such as search results from internal searches. In March 2007, Google warned webmasters that they should prevent indexing of internal search results because those pages are considered search spam.[46]
Lost IS (budget), aka “budget too low” – Do your campaigns have set daily/monthly budget caps? If so, are your campaigns hitting their caps frequently? Budget caps help pace PPC spend but can also suppress yours Ads from being shown if set too low. Google calls it “throttling” where Adwords won’t serve up ads every time they are eligible to be shown in an effort to allow your account to evenly pace through the daily budget.
The marketing automation coordinator helps choose and manage the software that allows the whole marketing team to understand their customers' behavior and measure the growth of their business. Because many of the marketing operations described above might be executed separately from one another, it's important for there to be someone who can group these digital activities into individual campaigns and track each campaign's performance.

There are several sites that claim to be the first PPC model on the web,[9] with many appearing in the mid-1990s. For example, in 1996, the first known and documented version of a PPC was included in a web directory called Planet Oasis. This was a desktop application featuring links to informational and commercial web sites, and it was developed by Ark Interface II, a division of Packard Bell NEC Computers. The initial reactions from commercial companies to Ark Interface II's "pay-per-visit" model were skeptical, however.[10] By the end of 1997, over 400 major brands were paying between $.005 to $.25 per click plus a placement fee.[citation needed]

The box on the right side of this SERP is known as the Knowledge Graph (also sometimes called the Knowledge Box). This is a feature that Google introduced in 2012 that pulls data to commonly asked questions from sources across the web to provide concise answers to questions in one central location on the SERP. In this case, you can see a wide range of information about Abraham Lincoln, such as the date and place of his birth, his height, the date on which he was assassinated, his political affiliation, and the names of his children – many of which facts have their own links to the relevant pages.
Thanks for the post Chelsea! I think Google is starting to move further away from PageRank but I do agree that a higher amoount of links doesn’t necessarily mean a higher rank. I’ve seen many try to shortcut the system and end up spending weeks undoing these “shortcuts.” I wonder how much weight PageRank still holds today, considering the algorithms Google continues to put out there to provide more relevant search results.

SEO techniques can be classified into two broad categories: techniques that search engine companies recommend as part of good design ("white hat"), and those techniques of which search engines do not approve ("black hat"). The search engines attempt to minimize the effect of the latter, among them spamdexing. Industry commentators have classified these methods, and the practitioners who employ them, as either white hat SEO, or black hat SEO.[49] White hats tend to produce results that last a long time, whereas black hats anticipate that their sites may eventually be banned either temporarily or permanently once the search engines discover what they are doing.[50]

Numerous academic papers concerning PageRank have been published since Page and Brin's original paper.[5] In practice, the PageRank concept may be vulnerable to manipulation. Research has been conducted into identifying falsely influenced PageRank rankings. The goal is to find an effective means of ignoring links from documents with falsely influenced PageRank.[6]
Some people believe that Google drops a page’s PageRank by a value of 1 for each sub-directory level below the root directory. E.g. if the value of pages in the root directory is generally around 4, then pages in the next directory level down will be generally around 3, and so on down the levels. Other people (including me) don’t accept that at all. Either way, because some spiders tend to avoid deep sub-directories, it is generally considered to be beneficial to keep directory structures shallow (directories one or two levels below the root).

Using keywords on the Display Network is called contextual targeting. These keywords match your ads to websites with the same themes. For instance, the Display keyword “shoes” will match to any website that Google deems is related to shoes. These keywords aren’t used as literally as Search keywords, and they’re all considered broad match. Keywords in an ad group act more like a theme. Display keywords can be used alone, or you can layer them with any other targeting method to decrease scope and increase quality.
You want better PageRank? Then you want links, and so the link-selling economy emerged. Networks developed so that people could buy links and improve their PageRank scores, in turn potentially improving their ability to rank on Google for different terms. Google had positioned links as votes cast by the “democratic nature of the web.” Link networks were the Super PACs of this election, where money could influence those votes.
In addition to ad spots on SERPs, the major advertising networks allow for contextual ads to be placed on the properties of 3rd-parties with whom they have partnered. These publishers sign up to host ads on behalf of the network. In return, they receive a portion of the ad revenue that the network generates, which can be anywhere from 50% to over 80% of the gross revenue paid by advertisers. These properties are often referred to as a content network and the ads on them as contextual ads because the ad spots are associated with keywords based on the context of the page on which they are found. In general, ads on content networks have a much lower click-through rate (CTR) and conversion rate (CR) than ads found on SERPs and consequently are less highly valued. Content network properties can include websites, newsletters, and e-mails.[7]

In February 2011, Google announced the Panda update, which penalizes websites containing content duplicated from other websites and sources. Historically websites have copied content from one another and benefited in search engine rankings by engaging in this practice. However Google implemented a new system which punishes sites whose content is not unique.[35] The 2012 Google Penguin attempted to penalize websites that used manipulative techniques to improve their rankings on the search engine.[36] Although Google Penguin has been presented as an algorithm aimed at fighting web spam, it really focuses on spammy links[37] by gauging the quality of the sites the links are coming from. The 2013 Google Hummingbird update featured an algorithm change designed to improve Google's natural language processing and semantic understanding of web pages. Hummingbird's language processing system falls under the newly recognised term of 'Conversational Search' where the system pays more attention to each word in the query in order to better match the pages to the meaning of the query rather than a few words [38]. With regards to the changes made to search engine optimization, for content publishers and writers, Hummingbird is intended to resolve issues by getting rid of irrelevant content and spam, allowing Google to produce high-quality content and rely on them to be 'trusted' authors.