In order to earn some income through blogging there are different kind of ad network are there the most common two ad networks are CPM and CPC ad networks. Both these ad network has different features.
CPM ad network allow the publishers to farm income through the traffic that they receives. The ad will track unique visitors whenever a new visitor comes into site.
Most of the CPM ad network a rate of 0.50$ to 5$. Chitika, adsense, clicksor are some of the ad network which pay good rates to the publishers for CPM advertisements.
But most of the advertisers never looks on CPM advertise because it is money loss thing rather than benefit so most of the them offers low CPM rates. Most of the small ad networks advertisers provide a low rate of 0.10$ to 1$ per 1000 views. But in the case of CPC ad network the rates are better than CPM ad networks. Most of the CPC ad networks offers 0.03$ to 0.14$ per click depending on the geo country targeted. CPM ad networks are extremely good for huge traffic generating sites while CPC ad networks are good for both low and huge traffic sites.
Some of the best CPC networks are adhitz, chitika, admediaclick there ad networks are offering good rates to the publishers because most of the advertisers prefers CPC advertisement. According to the clicks that recieves to the site the revenue of the site increases and decreases while CPM ad network some ad networks looks for unique impression which means there is no use with pageviews they need unique visitors. So CPC ad network is far better than CPM ad network. For generating good income with a site both the ad networks are extremely good. All the best.