What formula would you use to calculate Amazon DSP CPM using the fields available in dsp_impressions?
- (SUM(total_cost)/100000)/(SUM(impressions))*1000 AS avg_cpm
- ((SUM(spend)/100000000)/SUM(impressions))*1000 AS avg_cpm
- ((SUM(total_cost)/100000)/SUM(impressions))/1000 AS avg_cpm