As of 2009, there are only a few large markets where Google is not the leading search engine. In most cases, when Google is not leading in a given market, it is lagging behind a local player. The most notable example markets are China, Japan, South Korea, Russia and the Czech Republic where respectively Baidu, Yahoo! Japan, Naver, Yandex and Seznam are market leaders.
Google's founders, in their original paper,[18] reported that the PageRank algorithm for a network consisting of 322 million links (in-edges and out-edges) converges to within a tolerable limit in 52 iterations. The convergence in a network of half the above size took approximately 45 iterations. Through this data, they concluded the algorithm can be scaled very well and that the scaling factor for extremely large networks would be roughly linear in {\displaystyle \log n} , where n is the size of the network.

Page and Brin's theory is that the most important pages on the Internet are the pages with the most links leading to them. PageRank thinks of links as votes, where a page linking to another page is casting a vote. The idea comes from academia, where citation counts are used to find the importance of researchers and research. The more often a particular paper is cited by other papers, the more important that paper is deemed. 

nofollow is beyond a joke now. There is so much confusion (especially when other engines’ treatment is factored in), I don’t know how you expect a regular publisher to keep up. The expectation seems to have shifted from “Do it for humans and all else will follow” to “Hang on our every word, do what we say, if we change our minds then change everything” and nofollow lead the way. I could give other examples of this attitude (e.g. “We don’t follow JavaScript links so it’s ‘safe’ to use those for paid links”), but nofollow is surely the worst.
Google works because it relies on the millions of individuals posting links on websites to help determine which other sites offer content of value. Google assesses the importance of every web page using a variety of techniques, including its patented PageRank™ algorithm which analyzes which sites have been “voted” the best sources of information by other pages across the web.
A key objective is engaging digital marketing customers and allowing them to interact with the brand through servicing and delivery of digital media. Information is easy to access at a fast rate through the use of digital communications. Users with access to the Internet can use many digital mediums, such as Facebook, YouTube, Forums, and Email etc. Through Digital communications it creates a Multi-communication channel where information can be quickly exchanged around the world by anyone without any regard to whom they are.[28] Social segregation plays no part through social mediums due to lack of face to face communication and information being wide spread instead to a selective audience. This interactive nature allows consumers create conversation in which the targeted audience is able to ask questions about the brand and get familiar with it which traditional forms of Marketing may not offer.[29]

Yep, please change things to stop keyword stuffing. Change them to stop cloaking. Definately change them to stop buying links that try to game Google. But, telling search engines to not give weight (that I control) to pages that are not what my site is about or are not really relevant. No way. This is logical stuff here. Maybe too logical. I think deep down you know this Matt too.

Black hat SEO attempts to improve rankings in ways that are disapproved of by the search engines, or involve deception. One black hat technique uses text that is hidden, either as text colored similar to the background, in an invisible div, or positioned off screen. Another method gives a different page depending on whether the page is being requested by a human visitor or a search engine, a technique known as cloaking. Another category sometimes used is grey hat SEO. This is in between black hat and white hat approaches, where the methods employed avoid the site being penalized, but do not act in producing the best content for users. Grey hat SEO is entirely focused on improving search engine rankings.
When writing this guide, we reached out to the marketer community to collect case studies and learnings about creative marketing strategies. Most of these examples are included throughout the guide, but some didn’t quite fit. So we included those loose ends here, from the perspective of four awesome marketers. What better way to wrap up this guide than with you, our community?
By the way, YouTube currently is all over the place. It nofollows links in the Spotlight and Featured areas, where you assume there’s some editorial oversight. But since some of these show on the basis of a commercial relationship, maybe YouTube is being safe. Meanwhile, Videos Being Watched now which is kind of random isn’t blocked — pretty much the entire page is no longer blocked.
SEM, on the other hand, costs money but can deliver very rapid results. Your website must be optimized to make sales or at least drive a customer to get in touch (GIT – in marketing terms) so you can make a sale. You should approach SEM with care and make sure you completely understand how much money you have exposed at any one time. Start slow and evaluate your results.
Thank you, Brian, for this definitive guide. I have already signed up for Haro and have plans to implement some of your strategies. My blog is related to providing digital marketing tutorials for beginners and hence can be in your niche as well. This is so good. I highly recommend all my team members in my company to read your blog everytime you published new content. 537 comments in this post within a day, you are a master of this. A great influence in digital marketing space.
If you are going to use SEM, you must build the costs of using this form of marketing into your cash-flow forecasts and the prices you’re charging for your work. Spending $3,000 a month on Adwords to land $20,000 of business is eminently sensible in most cases. Spending $3,000 a month to land $3,500 of business, on the other hand, is likely to be a disaster for your business’s ability to trade effectively in the long term.
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.