ECommerce site being "filtered" by last Panda update, ideas and discussion

[WEB-IRS]

Hello fellow internet go'ers!

Just as a disclaimer, I have been following a number of discussions, articles, posts, etc. trying to find a solution to this problem, but have yet to get anything conclusive. So I am reaching out to the community for help.

Before I get into the questions I would like to provide some background:

I help a team manage and improve a number of med-large eCommerce websites. Traffic ranges anywhere from 2K - 12K+ (per day) depending on the site. Back in March one of our larger sites was "filtered" from Google's search results. I say "filtered" because we didn't receive any warnings and our domain was/is still listed in the first search position. About 2-3 weeks later another site was "filtered", and then 1-2 weeks after that, a third site.

We have around ten niche sites (in total), about seven of them share an identical code base (about an 80% match). This isn't that uncommon, since we use a CMS platform to manage all of our sites that holds hundreds of thousands of category and product pages. Needless to say, April was definitely a frantic month for us. Many meetings later, we attributed the "filter" to duplicate content that stems from our product data base and written content (shared across all of our sites). We decided we would use rel="canonical" to address the problem. Exactly 30 days from being filtered our first site bounced back (like it was never "filtered"), however, the other two sites remain "under the thumb" of Google.

Now for some questions:

Why would only 3 of our sites be affected by this "filter"/Panda if many of them share the same content?

Is it a coincidence that it was an exact 30 day "filter"?

Why has only one site recovered?

[WEB-IRS]

Thanks for your responses.

@EGOL - I would agree that merging the sites would be ideal given that they share such a large database. Unfortunately, this isn't an option for our company (at this point-in-time). Acquiring new content for our product pages has been tossed around, but would be a HUGE undertaking, so its on the "back burner" for the moment.

@Ben Fox - We came to the conclusion that it was content because it was the only clear "offender" on the list of potential problems. However, the fact that only 3 of our sites got penalized perplexes me as well. It would have made more sense had all of our sites suffered a penalty (luckily only 3 did). One response I got from another forum was: since google removed enough duplicate content (3 sites in our case) it deemed that the others were "original".

We didn't point canonicals to any one site (like 9 going to 1). We only added the rel=canonical to our manufacturer category pages (a small percentage of pages). Since some of our domains sell products that aren't "niche specific" we told these pages to send preference to their proper niche domain (hope that made sense).

For discussion purposes, here is a response I got from another forum:

Why has only one site recovered?I suspect/assume the other sites will bounce back the same way after their own 30 day penalties expire.>Why would only 3 of our sites be affected by this "filter"/Panda if many of them share the same content????? maybe removing the first site allowed the scoring penalty applied to the other sites to shrink in size.  as each site was removed, the penalty applied to the others correspondingly shrunk.  ?????>Is it a coincidence that it was an exact 30 day "filter"?No.  30 day is a common penalty.Does anyone agree with these? I've heard of the 30 day penalty before. If this is the case, then a warning from Google would be nice.

[EGOL]

Why would only 3 of our sites be affected by this "filter"/Panda if many of them share the same content?

Google can be slow to detect duplicate content and sometimes tolerates it.

Is it a coincidence that it was an exact 30 day "filter"?

Only google knows.

Why has only one site recovered?

Only google knows.

Google sees a lot of sites with same content and you say that these are "med-large" sites.  If I was google I would say... "these are dupe content, we aren't going to index all of them, our searchers don't want to see ten sites with same stuff".

If these were my sites I would merge all of them into one single site.   If the content on that site was unique to me I would probably then put all of my efforts into promotion and informative content for the product lines.

If the content was on other sites that I don't own then my efforts would go mainly into making unique product content and informative content for the product lines.

Google has been squashing duplicate content for years.  If you have it and you place links between the sites it is very likely that at least one of your sites will be demoted in google or filtered - probably filtered.  They don't want to spend their resources indexing ten duplicate sites.  They would rather display unique sites to their searchers.

[BenFox]

How did you decide that it was content causing the issue if only 3/10 of your sites were affected?

Also when you added the rel=canonical did 9 of your sites point to a primary site and was this the site that recovered?