The effective cost-per-thousand impressions (eCPM) is a useful way to compare revenue across different channels and advertising programs.It is calculated by dividing total earnings by the number of impressions in thousands.For example:
One of the best ways to improve the eCPM value is to see that the ads appearing on your site or blog are not of those of the MFA sites.I have published the list of MFA sites.Google has been trying to ban all the sites that list in those category. It is best on your side to add the sites to your competitive filter.
The next technique to increase the eCPM is to make your Adsense ads more and more visible.For this I dont think there is specific idea or formula but try making your ads embeded well in the content and bring them near the header of the web page.At urbanread we place our partner ads below the title and its the exact space where they are more visible.