Both of them need traffic. with CPM you need thousands of impression before any serious money can be earned. CPC is more content relevant and earning chances are more for newer sites.
Hi, Just to inform others that CPC means COST PER CLICK. CPM means COST PER THOUSAND IMPRESSIONS. CPM is always better if you have a high traffic site. CPC is always better if your content is pulling in traffic for high CPC keywords. Hope this makes sense. Regards, Wonay
the rule is simple , if you have thousands of visitors you should go with CPM you will generate enough money, otherwise just go with CPC.
If the web site getting huge traffic, CPM is a good option. However, Most of adwords advertisers are using CPC campaigns.
I do prefer CPC in one of my websites and CPM on other website. Because, i do get more impressions in one website but doesn't generate more revenue with cpc so i choose cpm and i can earn more..