Msg#: 4548560 posted 9:01 am on Feb 25, 2013 (gmt 0)
Big traffic change for top URL
Search results clicks for http://www.example.com/blog/ have increased significantly.
This message is not indicative of any problem in your site. It is simply to inform you that the number of clicks that one of your pages receives has increased recently. If you have just added new content, this may indicate that it has become more popular on Google. 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.
Check the Search Queries page in Webmaster Tools If this page is becoming more popular, you may use that as an indication to develop similar content in the future
Msg#: 4548560 posted 11:48 am on Feb 25, 2013 (gmt 0)
I get four of those messages between my sites in 2012. In one case Google had introduced the functionality of my page directly into the SERPs and users were not clicking through any more. In the other cases, it appeared that the page lost rankings for a particular keyword for no reason that I could discern.
Msg#: 4548560 posted 4:45 pm on Feb 25, 2013 (gmt 0)
I regularly receive those messages for my websites because my traffic can dramatically change due to seasonality and current events. Google also sends out notices when there are dramatic drops.
The more information we get out of Google is a good thing but I would be careful not to read too much into these messages. For example if you are making several changes to your site, it might not be the most recent change that caused the dramatic change spotted by this notice. Some parts of Google's algo have a delayed reaction.
If this notice is about a dramatic decrease of your site traffic then I would be grateful that Google is helping me realize traffic dropped. Most of my notices the drop was expected since I deal with seasonal traffic swings. Other times it would have helped me to spot content hijacking & competition but I had already spotted the drop myself.
Still a nice reminder to make sure you didn't forget to check analytics.