The problem with social networking sites is that you tag articles, but the links do not count when Google does its page rank calculations. I have sometimes seen a digg and readit in my list of links, but I’ve never seen del.icio.us. Technorati is always in the links. I listed 41 sites that are proven to generate a ‘legit’ inbound link from Google. Whether the value is 100% or not is impossible to tell.
I did research on several sites. One was www.marshable.com a site with 1.7 million inbound links…of which Google only recognized 609. This is a drastic problem when people are trying to build inbound links and increase their page rank and put their web pages on the tops of search engines (called Search Engine Placement)
One thing that many people do not know about link building is that older links are dropped, meaning that a website should try to add about 100 new links every month, if they want to stay at the top of the searches. Yes, this can be time consuming (100 links x about 3min per link if doing it like an SEM pro, no breaks = 5 hours. In reality, I find that IF I just worked on one URL at a time, it would take closer to 20 hours)


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