Making Money with Android

Admob - CPM Imps???

I have just seen that i am receiving CPM imps. I have never seen these before on my account. Could someone explain what they are and why i have only just started seeing them in my 3rd week of admob.

Thanks, James.

CPC impression … pays, when ad is clicked
CPM impression … pays already for showing ads (no clicks needed)

How come i have only just started seeing these?

Thanks, James.

As far as I know admob CPM imps are relatively new, or at least reports started to show them recently. Also, I have very very low number of CPM imps (compared to CPC). This is probably due limited inventory of these ads.