eCPM, or effective cost per thousand impressions, is a figure used to represent how well monetized your websites is. If your eCPM is $1 that means that your revenue is $1 per 1000 impressions - $1 is a low eCPM. If your eCPM is $60 that means that your revenue is $60 per 1000 impressions - $60 is a high eCPM. For Adsense, eCPM depends on two factors; the CTR (Click Through Rate) and the CPC (Cost Per Click). In this article I will discuss my 5 step process to achieving a high eCPM.

1. Write about high paying topics
   
   The CPC your ad clicks provide depends mainly on the topic you write about. For example, ads about finance pay far higher than ads about MySpace so if you can achieve equal traffic to a finance and a MySpace website the finance site will be more profitable, although MySpace websites may be easier to build traffic to.
   
   If you have already created a website on a specific topic you can still write about high paying topics within your niche. For example, if you were writing an article on web hosting using the keywords ‘paid web hosting’ will display higher paying ads than the keywords ‘free web hosting’. Small changes like this in your content can create big changes to your CPC and in turn, your eCPM.

http://all-seo-tip.blogspot.com/2008/05/5-steps-to-high-adsense-ecpm.html

Basically, it takes only four steps to set up referrals on your site. Review the steps below for a guided walkthrough of selecting and implementing referrals on your webpages.

Step 1: Choose your referral locale
Select the country and language combination for which you'd like to see available ads.

Step 2: Fill your Ad Shopping Cart
Choose from our extensive list of advertisers in a variety of different categories.

Step 3: Customize your ad unit
Design an ad with the size and color scheme that best matches the look and feel of your site.

Step 4: Copy and paste the code in your pages
Paste the referral code into the HTML source of your webpages and publish them to the web.

Step 1: Choose your referral locale

Before picking specific ads, you'll need to specify your country and language preferences. In order to maximize conversion opportunities, choose the combination that best reflects the profile of your users. Some referrals may not be available in all countries, even if they are available in your preferred language. Please note that if you select ads for a location other than the one your users are in that you may not get paid for the conversion.

http://all-seo-tip.blogspot.com/2008/05/referrals-quick-start-guide.html