Welcome to WebmasterWorld Guest from 126.96.36.199
Hard to guess on the basis of the small amount of information you posted, but one of the three ideas above might strike you as worth further investigation, so good luck!
Traffic got cut in half in May from Google, but ctr remained the same. After the traffic loss in May, I went from 1000 visits a day, to 500 unique visitors a day. I recently gained more traffic from Google in September, and I now get about 800-1000 visitors a day. I get a ton of referrals from Google images now, from the update, which I didn't expect. Even if the image referalls cut my ctr in half, that doesn't explain why my earnings were cut in half, since I am getting the same traffic on TOP of the google images traffic.
I was making most of my money from yahoo and msn referalls since I was basically out of Google, until Jagger. My yahoo and msn rakings have been retained.
Also, the ads seem to be on target...they are being rotated just as they were for the past 7 months.
Do you think update Jagger did this? Keep in mind my loss was on Oct. 2. Not sure when Jagger finished its update.
A particular advertiser that your visitors really went for stopped advertising? Yahoo or Google or somewhere you get traffic from made a big change, and started sending you visitors with different interests? Targeting of ads suddenly got worse overnight?
All of these or any of these. Personally speaking, and I really don't have any evidence to support this other than my own observations and the inferences gleaned from those observations, sudden changes in CTR usually equate to a particular advertiser having crafted a vary tasty ad that my visitors particularly found clickworthy. These changes in CTR were usually upward spikes that lasted for a day, maybe 2. Someone apparently having decided to try adwords and having written a very appealing ad and then after having tested it for a day or two decided it wasn't working and withdrawing from the program.
As hunderdown indicated, the type of traffic you get can do things to your CTR as well. I suspect you already know this. How did they arrive there and what is your visitors intent when they arrive at your website?
"We have the best prices for widgets on the internet. Secure ordering. Widgets shipped overnight!"
Will get you a certain type of visitor who's mindset is geared toward buying.
"FDA bans home widget use! Widgets determined to cause premature balding! Read about it here!"
Will obviously get you a different type of visitor. One is perhaps interested in buying a widget. The other wants to read and then leave, thus would probably be more likely to click.
Again, I'm sure you already know this. Even minor shifts in your traffic demographics can impact CTR
If it's cut in half it should be chop in 2 :-/
Hunderdown's idea could make sense, but there might be another explanation... Slow site performance can cut CTR and earnings quite dramatically. If pages are image intensive, for example, some surfers won't wait for the page to load. We've had two initiatives to reduce the size of our pages/improve load times, and following both initiatives the CTR and earnings immediately increased.
Could all this extra traffic be slowing your site down? Or is there something else you've done to the site (eg: added new/better/bigger images) which makes the pages take longer to load? If so, try optimising your images, to reduce file size, and see if CTR goes back up.