I've been using Google AdSense for a little over two years. Honestly, I don't spend enough time on the AdSense site. If I did, I might learn how to use AdSense more effectively.
A few days ago, I started making use Url Channels to keep track of how each of my domains is generating income.
I have one website [http://www.dumaguetecity.net/] and four blogs with Google ads on them. (I decided not to include ads on my meditation blog)
As of today, January 2nd, two of the urls have generated earnings ( albeit modest earnings ). The two blogs [sorryalltheclevernamesaretaken.blogspot.com and penpalwebsiteoftheweek.blogspot.com] use very different approaches to attract visitors who might make use of the Google ads.
The penpalwebsiteoftheweek.blogspot.com is set up to attract hits from people interested in one particular subject. Everyone going to that blog is interested in meeting someone via the Internet. All the Google ads on that blog reflect that and the sites advertised, obviously, appeal to the folks coming to the blog.
This blog uses the opposite approach. Here, I write about a wide variety of subjects in an attempt to attract as many visitors as I can. Looking at the Label list, one can see that I'm subject to write about anything that piques my interest on any given day.
Because of it's limited subject matter, the pen pal blog only manages to get 1/10th the number of visitors a month that this blog receives, but so far this month, they've generated similar amounts. After two days of monitoring the blogs individually, it's too early to tell which approach is better. At least now, with the url channels, I'll be able to look at each blog's performance over time.