How To Create A Custom Channel

The URL Channels are especially useful if you have several websites or
different topics discussed on different sections of your website, and you have
a general idea of the formats, colors, alignment etc. that works best for you.
But you still need Custom Channels if you want to track ads across different
domains based on placement, color, keyword or any other factor not included
in the Performance Report.
For instance, if I want to track left-aligned ads across all my websites (sites
with different domain names), I need to group them together into a single
channel and manually change the channel code for each page. On the old
interface, which many publishers are still using, it looks like this.
First, I name the new channel.

Then I choose the ad type, layout and color scheme of the ads I want to
track:

Finally, it’s simply a matter of allocating an alternate URL if I don’t want
public service ads, selecting the channel and copying and pasting the code
onto each of the pages that contain these kinds of ad.

The new interface makes things a little easier. Click the My Ads tab at the top
of the page, and when you create a new unit you’ll be offered a list of
channels to add to that unit. You’ll also be able to create a completely new
channel.
That layout is very useful because it means that you’re less likely to forget to
add a channel to every unit you create.
More importantly the My Ads tab also includes a custom channels section
where you can create new channels even without creating new units and
assign those channels to your current units without playing with any new
code.
So if you wanted to track all of the ad units that you’ve placed next to the
navigation bar on your sites, for example, you could create a new channel,
and add those units you’ve placed next to the navigation bar. It’s very
straightforward and very useful.
You can use up to five channels on one ad unit, letting you collect different
information about the same ad. When you check your channels, you’ll be
able to see how all your leaderboards or doing, as well as all your ads related
by topic or color.
That’s a huge help when it comes to understanding what your site is doing.
Custom channels provide such a broad range of information — from how
different locations are doing to how particular types of ad units affect your
revenues — that without them, you’re working in the dark.