My site was stable doing fine for last 2 years, but just 2 weeks back it's traffic dropped all of sudden by 35-50%. After 4-5 days of this I received this message(below after --- line) from GWT.
For the last week I've been trying to figure out the problem but to no avail. I've checked for malware etc but nothing found. I understand something abnormal has caused Google to send me this notification, which isn't due to any algorithmic updates. Any guess what could be the reason? In my shared account other sites have been stable.
http://goo.gl/oV9l9 : Big traffic change for top URL
Search results clicks for http://goo.gl/EMASI have decreased significantly.
The number of clicks that your site receives from Google can change from day to day for a variety of factors, including automatic algorithm updates. However, if you have recently made significant changes to the content or configuration of your site, this change may be an indication that there are problems.
Check the Search Queries page in Webmaster Tools Investigate whether the traffic change affects the whole site or just a few pages. Configuration changes are likely to affect the whole site Some content is popular only for a short window of time. If the change in traffic affects only this kind of content this message may not be indicative of any problem