After the last three dismal months with earnings continuing to fall, I decided to contact Google. I receive reply with steps into looking into where the decrease began, etc. Then states:
"Now that you’re viewing the appropriate metrics to determine what may have led to a recent decrease in earnings, try to evaluate if your ad requests, clicks, CPC, or ad request CTR fell when your earnings dropped. Taking a look myself, it looks like the number of clicks have dropped off most significantly for you."
THERE IS NO WAY TO DETERMINE THROUGH METRICS WHY CTR DROPPED.
So I kindly replied, "How can I determine the cause of the problem through these metrics which only show my decrease, which I am fully aware of? Am I missing something?"
Her second email response:
"No there is nothing obvious you are missing. Diagnosing earnings decreases are very difficult as it could depend on numerous changing factors and variables. It could be seasonal, change is visitor habits, ad blindness, or many, many other various factors."
<sarcasm>WELL THIS IS HELPFUL</sarcasm>