Google Adsense Account can now easily be integrated to Google Analytics Account. Both the services are completely free. Users now can dig more deeper into their Adsense tracking and get indepth reports about their blogs.
Also they can setup one blog as a primary one and do not have to even change the tracking code on it. It is great and there is no reason for not using it, unless you do not use Analytics itself.
Below is the video for the clear explanation