Welcome to WebmasterWorld Guest from 126.96.36.199
we have many websites. One of them is the main website. and others are subsites, but they share the same company brand, logo; and part of product, content are almost the same (Not exactly the same).
"Is there some reason you feel that your ranking changes are a true penalty (something manipulative that Google wants to punish) rather than just rankings that went lower? "
So how are they DIFFERENT from one another? They sound almost identical...
If you can let us know how they differ significantly from one another, we might be able to better help.
...content are almost the same (Not exactly the same)...
- Does the site have duplicate, overlapping, or redundant articles on the same or similar topics with slightly different keyword variations?
- Does the article provide original content or information, original reporting, original research, or original analysis?
- Does the page provide substantial value when compared to other pages in search results?
...so, if google realized that these websites are belong to one company, and because these websites have the same content between the main website, so these subsits were penalized?
...and it may well be that, on Dec 19, Google adjusted its duplication threshold, or that it made adjustments to how it valued the inbound link juice your sites were getting, or any of a number of factors.