There are many types of advertisements over the internet now a days. But the most popular ad formats are CPC and CPM. Most of the ad networks pay the publishers on impression basis. But some big ad networks like Google pays you impression + clicks based.
Pay per click (PPC) or Cost Per Click (CPC):
Pay per click advertisements are the format in which whenever someone clicks on your ads you get paid. Cost per click is the same format like pay per click, like whenever someone clicks publisher (website owner) earns money.
But these click rates vary country to country, USA, UK, Canada, Australia are the highly paid countries, European countries gives you less click rate then these highly paid countries. Asia and middle east are at the bottom in the list. You can get an idea through the following chart. It’s not a fact but just an assumption to give you the idea of click rate difference:
Highly paid countries: 1 click = $ 0.50
European Countries: 1 click = $ 0.10
Middle East countries: 1 click = $ 0.08
Asia : $ 0.05
India & Pakistan: 1 click = $ 0.02 or 0.03
CPM Cost per Mile:
Cost per mile means you will get paid on each 1000 impressions, like if your CPM rates are $ 0.50 and you have 10,000 impressions per day so you will earn $ 5 each day. But impression rates depends on the traffic destinations like PPC.