Negative Factors When Building Links: Readers have asked me this several times: Is there such a thing as a “bad link?”
Well no link to your website can have a negative effect, due to you not having control of who links to you, however as we know, links from different sources can have different values, some even having no value, rendering them worthless apart from traffic. Aside from “nofollow” here are some other links that won’t help you:
Duplicate Content: It is a common misconception that you will get penalized by the search engines for posting duplicate content, this is actually incorrect. Search engines will never give you a penalty for using the same content as another page, but what they will do is just give your page no value, which means any links on duplicated page will be worthless in terms of Page Rank. Duplicated content will more than likely leave you in the “supplementary index” Non-
Relevant Content : Just as links on pages providing relevant content are extremely powerful, the inverse is true for pages providing irrelevant content. For example a link to Viagra page from a fishing page will be devalued, there’s no saying that fishermen wouldn’t be interested in Viagra, but generally it isn’t a helpful resource to people looking for fishing information.
Hidden Links: Search engines can detect if something is suspicious, for example white text on a white background or anything else that would appear invisible, if you do things like this on your pages search engines may mark you as ‘black hat’ or some kind of spam artist.
Non-indexed pages: If a page is not indexed then you can guarantee any links on it will have no value in terms of Page Rank, there are two reasons a page may not be index, the search engines have not found it yet, or they have found it and chosen not to index it for some reason.
Illegal, adult or black hat websites: I like to categorize these sites as inappropriate, we don’t really need sites like this on the web and definitely shouldn’t endorse them, I would never recommend requesting a link from one of these sites, firstly they have no value and secondly it’s unethical.
Link farms, clouds, ect.: Websites and groups made with the intention of the users trying to manipulate search engine rankings will be discovered hastily by the search engines, an example of this is buying a dropped domain with Page Rank and creating a ‘link cloud’ on it and selling links. Websites on the same IP.
If two websites have the same IP it is very likely the same person who is using the same hosting account owns them, for this reason links between the same IP are devalued just as internal links are.
Feel free to comment any that I might have missed