If you are into upgrades, Google is now offering AdSense Premium, which is CPC based and, for the time being, offers less flexibility in terms of ad sizes — only banners and skyscrapers are currently available. You can apply using existing AdWords accounts, or you can request a new account. Applicants are usually notified within a day as to whether theyve been accepted for the program.
Heres the thing you need to know: Google has no strict criteria for acceptance into the AdSense program, and Ad Sense doesnt hit you with a minimum traffic requirement. The only criteria theyre really sticky about is the standard acceptable content requirements, and thats pretty standard almost anywhere.
Google AdSense says theyre serious about attracting quality content sites, and because of that they only allow AdSense members to serve one ad per page. This means you cant use AdSense for both banners and skyscrapers.(Note: banners are those horizontal ads that run up top and down bottom. Skyscrapers are the tall ads that run vertically, on the left and right of your page text.)
Once youve been accepted into Google AdSense, youll be able to get the AdSense advertisements on any site you own using the same ad code, provided you obey the Google guidelines. (And thats very, very importantmore on that later.)
Your reporting doesnt occur in real time, but is updated regularly throughout the day. Right now, you cant view reports based on a domain or site basis if you run the AdSense on more than one site.
Before you sign up, you really ought to read the lengthy and detailed FAQ on the AdSense site.