Hi, I had around 35 niche specific content sites. They were created around 1 month back and just 10 days back, they started gaining SE traffic. Now 3 days back, when I logged into my webmaster tools account I checked that there is a warning 'This site may be in violation of Google's quality guidelines' and today when I checked the indexed pages, most of the sites are banned from Google. I'm giving the URL of one of my site. All the sites follow the same theme and same format. I tried to analyze everything and I'm not able to pinpoint what is the mistake. Here is the URL of one of my sites http://asthma-remedy.net/
The mistake was you created 35 sites. Probably auto blogs right? Content not unique? Yeah, what do you expect? Those types of sites offer nothing valuable to google.
IMO, you need to check through google's quality guidelines, and to see whether yours sites are in violation to these rules, surely you will find the reason.
Which is exactly why I'm here. I checked Google Quality Guidelines but I couldn't pinpoint even a single one which would have caused my site getting banned from them. Does anyone know what is the problem with my site