Without going into details. The company I work for has potentially millions of pages indexed. Despite new content being published everyday, since around the same October dates we are seeing a decrease in the number of indexed pages.
We have a consultant for the topic but I am not sure how much of that conversation I could share publicly so I will refrain myself of doing so.
But I think I can say that it is not only about data structure or quality. The changes in methodology applied by Google in September might be playing a stronger role than what people initially thought
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