In an effort to manually control the flow of PageRank among pages within a website, many webmasters practice what is known as PageRank Sculpting—which is the act of strategically placing the nofollow attribute on certain internal links of a website in order to funnel PageRank towards those pages the webmaster deemed most important. This tactic has been used since the inception of the nofollow attribute, but may no longer be effective since Google announced that blocking PageRank transfer with nofollow does not redirect that PageRank to other links.
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.
Labels are like Post-It notes and built-in documentation for campaigns, ad groups, keywords, and ads. Labels can be used for anything, from ad creation dates to top performing keywords. Labels are especially useful in accounts with multiple account managers or specific segments with varied goals. Once properly applied it is much easier to assess campaign performance for a specific initiative.
Just like the world’s markets, information is affected by supply and demand. The best content is that which does the best job of supplying the largest demand. It might take the form of an XKCD comic that is supplying nerd jokes to a large group of technologists or it might be a Wikipedia article that explains to the world the definition of Web 2.0. It can be a video, an image, a sound, or text, but it must supply a demand in order to be considered good content.
Links still matter as part of the algorithmic secret sauce. The influence of a site’s link profile is plain to see in its search engine rankings, whether for better or worse, and changes in that link profile cause noticeable movement up or down the SERP. An SEO’s emphasis today should be on attracting links to quality content naturally, not building them en masse. (For more on proper link building today, see http://bit.ly/1XIm3vf )
The flat-rate model is particularly common to comparison shopping engines, which typically publish rate cards. However, these rates are sometimes minimal, and advertisers can pay more for greater visibility. These sites are usually neatly compartmentalized into product or service categories, allowing a high degree of targeting by advertisers. In many cases, the entire core content of these sites is paid ads.
Content type: Many search features are tied to the topic of your page. For example, if the page has a recipe or a news article, or contains information about an event or a book. Google Search results can then apply content-specific features such as making your page eligible to appear in a top news stories carousel, a recipe carousel, or an events list.
Webmasters and content providers began optimizing websites for search engines in the mid-1990s, as the first search engines were cataloging the early Web. Initially, all webmasters needed only to submit the address of a page, or URL, to the various engines which would send a "spider" to "crawl" that page, extract links to other pages from it, and return information found on the page to be indexed. The process involves a search engine spider downloading a page and storing it on the search engine's own server. A second program, known as an indexer, extracts information about the page, such as the words it contains, where they are located, and any weight for specific words, as well as all links the page contains. All of this information is then placed into a scheduler for crawling at a later date.