If you want to make more from Adsense then you will need to understand the reports and channels eCPM and CPM ads are often confused as there are sometimes you earn without clicks but this does not happen very often for most niches.
What is the Difference between eCPM (effective cost per thousand) and CPM(cost per mille)
Many New Adsense Publishers still do not understand the difference between eCPM and CPM ads so what are the Differences Between eCPM and CPM.When you are a publisher using Adsense you may hear people talking about eCPM and and CPM in Adsense Debates and Topics basicly eCPM is a Reporting feature and CPM is the Amount of Money you will get per 1000 impressions.
What is eCPM
Just say a Publisher has a site we will call it example.com and the Adsense Publisher is Looking at their Adsense Reports and they See that they Earned $0.25 from 100 Adsense Impressions. This means that the Publisher if this Pattern Continues will earn $2.50 from 1000 Ad Impressions.In short it is your earnings divided by the Number of Impressions and Multiplied by 1000
With CPM ads the Difference is that someone is paying per impression for that ad to run on example.com so example.com has a CPM also know as CPI or (cost per impression) ad running on the site.This is because an Advertiser though that they would like to have an Ad Running on example.com and are willing to pay $4.00 for every 1000 views his Advertisement gets.While the CPM Ad us Visible on example.com they will earn $4.00 for every 1000 views that Advertisement gets.
Why is eCPM Important to Monitor
It is Important to Monitor your eCPM and See if you can Improve it because if it is too low then you will not be Expecting to be Earning Much from Adsense unless you change some things like Placement or using Higher Paying Keywords.
Getting CPM Ads on your Website
CPM Ads will Rarely run on Most Websites you will sometimes have a CPM ad running where you will see earnings but no clicks these types of ads are mainly highly targeted and count yourself lucky if you are getting them.