SEO Case Study: The Panda Update Investigating Ads Per Outbound LinksPosted by Ben Sibley on Apr 7, 2011 | 4 comments
This is an SEO Case Study exploring the effects that ads per outbound links and their ratio has had on the SERPs since the public update.
After the Panda/Farmer update a month ago, many major sites got hit VERY hard in the SERPs. There has been a lot of speculation and research since as to what factors have changed and where the weight has shifted between these factors. I decided to conduct some of my own research to gain further insight into the update and some changes that were made and document it in this SEO case study.
Something that content farms often do is abuse Adsense. I did a test to see if I could find some sort of correlation between the use of Adsense and some of the sites that were most negatively affected by the algo change. I wanted to see if sites that linked out more to ads than real sites got hit for it.
“…parts of our system encourage links to good sites.”
“…good pages seldom point to bad ones”
- The TrustRank White Papers (http://www.vldb.org/conf/2004/RS15P3.PDF)
The ads don’t necessarily lead to bad sites. Quite contrarily, they often lead to authoritative pages. I bring this up simply to point out the fact that Google uses your outbound links as a factor when ranking your site. So, if content farms typically have a larger percentage of outbound links that are ads, it is plausible that Google might have started using this as a measurement in their algorithm.
I took a random sample of 5 article pages from each of these sites and measured their adsense links to OBL (outbound link) ratio as well their adsense to overall links ratio. Here’s what I found:
(In order of most negatively effected by the update to least)
Ad Links/Total Links = 14.5%
Ad Links/Outbound Links = 54.14%
Answerbag.com – Change: -91%
Ad Links/Total Links = 11.72%
Ad Links/Outbound Links = 60%
Buzzle.com – Change: -85%
Ad Links/Total Links = 21.79%
Ad Links/Outbound Links = 92.42%
Wisegeek.com – Change: -77%
Ad Links/Total Links = 15.93%
Ad Links/Outbound Links = 67%
As we know, Ehow.com was one of the major winners in the most recent update. Here’s what I found for them…
Ad Links/Total Links = 10.28%
Ad Links/Outbound Links = 38.83%
The samples were relatively small, and the data doesn’t correlate to precisely with my hypothesis. However, in the test I conducted, Ehow’s Ad Links/Outbound Links ratio is noticeably lower than the other sites’. This leads me to believe that one of the ways Google tried to target content farms is by cracking down on sites who mostly link out with ads. As further evidence, I cite Chris Knight’s blog (the SEO of Ezine Articles) – http://blog.ezinearticles.com/2011/02/search-engine-algorithm-changes.html#more-11693.
In his blog entry directly following the update, he lists a few major changes Ezine will be making. The third point he makes is lowering the amount of ads per article page. Hmm…
He says it’s to provide a better user experience. Wait, who have we heard that from?
Provide a better user experience, follow Google’s webmaster guidelines, and rank higher. That’s pretty much as clear as Matt Cutts ever gets to giving SEO suggestions. While there were undoubtedly many major changes in the Panda update, this seems to be one less noticed aspect in the algorithm change.
(Data gathered from SISTRIX: http://www.sistrix.com/blog/985-google-farmer-update-quest-for-quality.html)
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