I wonder whether all the Analytics users can see the AdSense earnings. Seeing the earnings in analytics would be very useful for me, but I wouldn't like all my analytics users to see this particular bits of stats.

I was curious why you have to add more code to see these stats in Google Analytics. I already have AdSense and Analytics code in my pages, why is more needed? I am already leery about the load times of all the Google javascript in my pages, so I'm not going to add any more.

Chris, I was also curious about this point. Here's Google's reply though it doesn't specifically mention why it is needed:

<<For the linking to work, is it necessary to enter the window.google_analytics_uacct = "UA-foobar" script bit even into pages which already contain both the Analytics and the AdSense code?

Yes, if the page is not chosen as your primary domain – you designate one tracker as primary during linking (UA-xxxx-a), and the non-primary trackers (UA-xxxx-b/c/d/...) require this third piece of code. See https://www.google.com/adsense/support/bin/answer.py?hl=en&answer=98142 .>>

Chris: the extra AdSense Analytics code is just one line of JavaScript which assigns a string to a variable. It doesn't download another script, and won't add any significant load to your page.

Thanks for the replied, both Philipp and Roger.