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All, Hope you are having a good day! Recently I had a strange issue with one of my site and I am not sure what might have caused it. I am sure this would be a good place to discuss about it and get some feedback from the elite people in the industry. Here is the problem. Last weekend (On sunday noon) my site which was ranking on Page 1 suddenly dropped its ranking for its main keywords to nowhere, I was  panicked to see what was happening and by the end of the day it was slowly coming back and by next morning everything was back. Again on Wednesday noon, the same thing happened. However, this time it din't come up by the next morning. Making it worse, all of my keyword rankings went down from good spots to no where and there was a point when I could no longer see my site. I was worried something might have happened this time and was not sure what could the reason be. On Friday afternoon all the ranking came up better than the previous (which is a very good news for me). At the moment, my site is doing very well and I am really happy about it. I did realize that Google was updating their Algorithm, but this behavior is the strangest I have seen over years. Can someone enlighten me on this peculiar behavior. Is there something wrong with my site or is it a common thing that I have never noticed?  I have never done anything blackhat for the site. To be honest, all I have done is some low level link building on the site and the site had some advantage of a re-direct from one my previous site which was doing very well in search engines (I changed it to take advantage of the new domain I had). Your opinions/suggestions are a appreciated.