Google Engineer Explains What May Cause a Penalty

SEO-Scoop has a great post on Google algorithm. Below is a quote but make sure you check the SEO-Scoop Blog:

The question asked of the Google engineer was in regards to whether or not Google penalizes or filters a site that has a sudden influx of new pages. This was the explanation given (paraphrased)…

Google does not specifically filter for any one particular thing like that. Instead the algorithm looks at other similar situations and determines if the action is good or bad. For example, if a 2-page site suddenly adds 10,000 pages, there may in fact be a legitimate reason for it to do so. But the algorithm will first make the assumption that the action is “suspicious” and will then look at a large sample of other 2-page sites that have suddenly added 10,000 pages. If the majority of those sites were considered spammy, then your site will get lumped into the same spammy category. Of course, if the majority of those sites were deemed to be legitimate, then your site would likewise be deemed legitimate. Basically, he admitted that there may in fact be absolutely nothing wrong with your site, but it may be filtered or penalized if it fits the profile of other sites that have been marked as spammy.

He suggests that if your site falls into such a category (of being legit, but being lumped into a spammy classification), then you should let Google know about it. He implied that the matter would be looked into, and that the algorithm may be adjusted to be able to handle situations like yours in the future, but that nothing may be done to directly impact your particular site (other than adjusting the algorithm in general).