In Google’s Adsense, you can use channels to separate out the stats for different sources of ad clicks.
This is useful, for example, if you have two different niche sites and you want to know how much each makes. Without using different channels, the stats for each site would be lumped together.
Up until fairly recently, I’ve been using custom channels, where you’re given a bit of custom code to put in your web page. I understood how to use custom channels, and just stuck with them.
Another sort of channel you can use is a URL channel. With a URL channel, you put the standard Adsense code on multiple pages in a site, and then Adsense itself splits out any stats that come from the given URL. Useful if you have a lot of pages on a given site, and don’t care which page specifically gets the clicks.
But I still used custom channels, because you could do the same thing with them. Then I discovered a situation in which URL channels are the only possibility.
But neither allows you to enter a custom channel id, so you cannot use custom channels to separate the stats for the sites. You can, however, enter URL channels for each and Adsense will separate out the stats for you.
Entering a URL channel is easy. You click on the link to add a new URL channel, and then enter the domain name of the site (e.g. quassia.com).
After that, the stats are properly separated automatically.
I hope this has been of use to anyone who, like me, wasn’t sure what URL channels were good for. While you can use either URL or custom channels for most things, in this particular situation URL channels are the only solution.