I have 8 sites on a single server and I have noticed that all 8 sites ranking is down to 5-6 pages while it used to stay in top 10 listings for their relevant niche keywords. So, it could be penalty on ip?
Usually IPs don't get banned because there is a shortage of them and hosting sites often put 100s of them on one IP, which Google recognizes. Are all your sites on one IP? If you want to rule it out as a cause and depending upon the type of hosting package you have, you may be able to get a new IP. More importantly, do all these sites link to one another? This could be an issue if they are all on the same IP
Same question, how are they interlinked Mong? I've experienced the same thing you have mentioned, all sites on a server nailed and even adding new sites "not" interlinked with the others saw penalties applied to them despite being 100% clean/organic. Another question, were these sites running the same Whois, Adsense or Analytics accounts? Basically, is there anything common to them all besides the IP?
ALL my site sar ehostedon the same IP aswell. While I have not seen my sites fall in ranking I have always felt that my sites do not rank as well as they should compared to the amount of time I put in every day on search engine optimisation and marketing. Do you think getting a second ip address on the same server and splitting the website to different ip addresses help or would that be seen as being on the same server.
Probably your ip range on spam blacklist.Check with your host if your ip are clean and is not in blacklist.
Crosslinking and IP Addresses might be the reason for such a penalty, do check any common info on those websites: even whois records and google accounts might be the same !!?
This could be that the ip is on a blacklist but I doubt it. We had some sites on the same server and different ips. The sites were not interlinked and not on any blacklists. Thet all dropped signficantly during one reindex. I changed the CMS to Wordpress and all was solved. The sites shot back up. It was a keyword relevancy issue because a lot of web sites entered into the mix and we simply dropped.