Robert_Charlton - 10:24 am on Jul 28, 2013 (gmt 0)
More about "upstream"... The word is very descriptive about how link juice flows, and I use it a lot when discussing backlink changes on the web. Here are some quotes from a couple of my old posts that could easily apply to what we're talking about now. IMO, "upstream"... at the source... is a logical place for the spam team to be looking.
Does Google "Age" Your Backlinks?
All linking pages are subject to changing conditions upstream of them... anything from code changes to business changes to algorithmic changes, all of which can positively or negatively affect inbound link juice. Some pages have good enough content to attract inbounds once they become sufficiently visible, which can mask other upstream changes. In some market areas, links will be affected by upstream link buying and selling as well....
And, with regard to Penguin-affected sites...
65% of Poll Respondents Report Negative Penguin Impact
I'd like to see a much more granular exploration of those who were affected, as I'm thinking that the poll may also be skewed by types of sites and types of SEOs.
I'm suspecting in many cases that upstream link sources have gotten hit... and I'm guessing that the further away from the SEO industry the link sources were, the less likely it is that they were "tainted". This is completely gut level... I haven't done the kind of study necessary to be more sure of the causes than this educated guess... but from what I've been seeing, there haven't been many surprises.