I'm making up numbers here. Let's say I am in my Google Reports, and under Page eCPM it says $40. Then under Earnings it says, for example $30. Now under my Totals, it only shows that $30. Why isn't eCPM calculated in my totals? And why does it show that sum if it isn't calculated into the totals?
Because eCPM (stands for "effective cost per 1.000 impressions") is a statistical figure meaning that if, say, 2.000 impressions made you earn $10.00, then your eCPM= 10.00 / 2 = $5.00. Statistically, you earned $5.00 for each 1.000 impressions. Hope it helps.