Keywords Searchers Google Index and Adwords Advertisers
Thanks for commenting again, Humagaia ;-) Please note that I put the two intentionally together as in
"from a spammy site to an completely unrelated one is worth nothing."
What you describe, a link from a site that has some sort of Google trust, even if little, to an unrelated one would have some, but little, value in my experience. So in the scale of valuable links it would be close to the bottom, but not the least valuable one, you are correct. I simply wanted to show of the two extremes of the spectrum.
As for anchor text, also here things seem to be changing. It is true that anchor text is important, but it also seems to be true that it is important how the link is presented. It seems to me, and other seo nuts I speak with ;-), that Google takes more and more the wider text in account that surrounds the link, not only the actually linked text. Staying with your example, how does this link look to you?
"Our singywingy tablets cure wotsydangle, which can be caught when cleaning out ferret cages. If you have no idea how to do this safely, here a great article I really like about [ferret cages] [linked] and how to clean them safely."
Me, and others thinks that Google is slowly re-evaluating the real value of perfectly anchored back links in a text and is looking at the context to see if the link was fabricated or if it is a real recommendation. Because that is what a link is, a recommendation from one site to another.
As for "The link value passed from the pharma site is related to the number of external links, total links and PR of the site where the anchor text resides."
Plus the trust rank Google has assigned to that site, which can be very different from pagerank. For the rest you are again correct ;-)
Sam, Jan 28, 2012