For the last year, I saw how my efective CPM varied from around $24 for a week or two, than go down to $18 for another week or two, then go back to $24 and so on.
But since the last week of december, the CPM was down to arround $18 and it never came back again. Four weeks in a row with this low CPM.
Has Google announced they are calculating smart pricing in different way now?
Are they now just taking more times within updates? I thought it was updated weekly.
