two month ago i discover something strange with my adsense profit behavior then i spend one month to proof it, result is like what i expect ....

This is what happen :
I run web site using blogging platform (wp), around 3000 thread update daily, what i found is, if i make update on the day, my CPM will be 0.9 to 0.5 but if i stop updating data, my CPM will increase to 1.3 to 1.8 .....

So i try update new post in every alternate week, yes the result is what i predict, the week update i have low income, the week i do nothing my income will be higher .....

just strange i'm not sure why this happen ... keyword target is same and all traffic basically from same type of keyword


any expert can explain ?? thanks