While Google never sells better ranking in our search results, several other search engines combine pay-per-click or pay-for-inclusion results with their regular web search results. Some SEOs will promise to rank you highly in search engines, but place you in the advertising section rather than in the search results. A few SEOs will even change their bid prices in real time to create the illusion that they "control" other search engines and can place themselves in the slot of their choice. This scam doesn't work with Google because our advertising is clearly labeled and separated from our search results, but be sure to ask any SEO you're considering which fees go toward permanent inclusion and which apply toward temporary advertising.

We have to remember that Google’s $ model+bots to scour the web have to tow the same line so they can optimize their own pocketbook, balancing a free and open resource – ie. the www, all while taking money from the natural competition that arises from their market share. On the one side, its all about appearing fair and the other, to drive competitive output.

One common scam is the creation of "shadow" domains that funnel users to a site by using deceptive redirects. These shadow domains often will be owned by the SEO who claims to be working on a client's behalf. However, if the relationship sours, the SEO may point the domain to a different site, or even to a competitor's domain. If that happens, the client has paid to develop a competing site owned entirely by the SEO.
All of the examples above and more could be used as anchor text for the same backlink. Google will index each differently. Not only that, Google will even examine the few words before and after the anchor text as well as take into account all of the text on the page. It will also attribute value to which backlink was first in the page and diminish the value for each following link.

Well, to make things worse, website owners quickly realized they could exploit this weakness by resorting to “keyword stuffing,” a practice that simply involved creating websites with massive lists of keywords and making money off of the ad revenue they generated. This made search engines largely worthless, and weakened the usefulness of the Internet as a whole. How could this problem be fixed?
A navigational page is a simple page on your site that displays the structure of your website, and usually consists of a hierarchical listing of the pages on your site. Visitors may visit this page if they are having problems finding pages on your site. While search engines will also visit this page, getting good crawl coverage of the pages on your site, it's mainly aimed at human visitors. 

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.
Another reason is that if you're using an image as a link, the alt text for that image will be treated similarly to the anchor text of a text link. However, we don't recommend using too many images for links in your site's navigation when text links could serve the same purpose. Lastly, optimizing your image filenames and alt text makes it easier for image search projects like Google Image Search to better understand your images.
PageRank is one of many, many factors used to produce search rankings. Highlighting PageRank in search results doesn’t help the searcher. That’s because Google uses another system to show the most important pages for a particular search you do. It lists them in order of importance for what you searched on. Adding PageRank scores to search results would just confuse people. They’d wonder why pages with lower scores were outranking higher scored pages.

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