Hi! We’ve been running 113 dating banners via iframe on RON DE. All banners received the same amount of impressions.
We have waited until banners with zero conversions were proven to be worse than the best converting one by Chi Sq. (http://www.evanmiller.org/ab-testing/chi-squared.html). We have taken away «zeros». There was approx 30% of them.
Than we have waited until banners with 1 conversion were proven to be worse than the best converting banner. We have eliminated 1-s too, also approx 30%.
But the thing is that eCPM HAS NOT CHANGED! In fact it got even worse a bit.
How is that possible? What we have done wrong?
eCPM is the effective cost per thousand banner impressions. So if you remove banners with a low CTR or CVR the eCPM will stay the same. the only thing that will get lower is your CPC if you remove the banners with a low CTR.
We have compared banners against their impressions/conversions ratio (trials/success in Chi Sq), so CTR and CPC do not matter as they are "already included".
Any other ideas? Here are some figures:
The whole amount of impressions received by campaign: 29,899,082
The amount of impressions after which «zeros» were taken away: 6,591,990
The amount of impressions after which «1-s» were taken away: 7,182,920 (590,930 after «zeros»)
As a result of «optimization», the eCPA increased by $0.23
i don't really get your question. are you paying a fixed cpm? or have you bought a whole spot for a month at a fixed price? or are you paying cpc?
It was RON (Run on Network) SmartCPM close to minimal