I think the larger question is whether a channel has any effect on CTR, eCPM, etc. Maybe that's the question you should ask.

FarmBoy

I guess where I'm confused is if Advertisers are targeting a channel and it's paying well wouldn't it make sense to add that channel to other ads? What I'm worried about is that this will then dilute/destroy the channel that's paying well...but I don't know if that makes any sense.

Do you know for sure that it is targeting that is creating the high eCPM in that channel? It may not be. It may just be that the regular CPC ads there are higher-earning than the ads in the other channel....

Almost certainly if you deploy on more pages your ecpm etc will drop.

I can tell you that I have a channel that covers about 50 pages, I should split up the pages into more channels, but I am too lazy to do the rework on the web site. It is a very high earning channel, and it is covering at least 50 pages. The reason the channel covers so many pages is that all the pages are very similar. I made the channel and the pages a long time ago, when I first started with AdSense.

The disadvantage to having so many pages covered by one channel is that you can't tell what is making the most money within those pages.

[edited by: ArtistMike at 4:44 pm (utc) on Dec. 3, 2008]

Good question purplecape...and I don't know the answer. ArtistMike - On my pages (about 1000) that use the same format I have 4 different ads each assigned a different channel name so I can tell which ads are producing the best. It's consistently a 160x600 ad if that helps anyone.

coachm - could you elaborate on why the eCPM would drop? Just too much saturation of a channel?

Regards,
bgd2006

I would also tend to assume that the eCPM would drop. Don't know what you mean by "saturation of a channel" but if you mean you'd soak up the demand for the keywords appearing in it, no, because it seems unlikely to me that any one publisher could do that, unless there just aren't many advertisers.

I assume the eCPM for your existing channel would drop because you'd be mixing in pages with keywords that are attracting lower-paying ads into a channel with pages that are attracting higher-paying ads.

I base that on a further assumption: that the two channels are not attracting exactly the same ads. Given the number of pages in the larger channel, in fact, I assume it is rather heterogenous--that you are getting a mix of different advertisers chasing a mix of different keywords.

Unless you carefully build them up, channels are really just buckets into which you have grouped your ads or pages. The pages or ads in them may not have a lot in common....

Do you see what I mean?

purplecape - I think you hit the nail on the head. The two channels are attracting different sorts of ads. If the eCPM for the higher smaller channel dropped that wouldn't be such a bad thing if it raised my eCPM for the other channel which gets about 30-40 X more views per day. I guess the only way I'll really know if adding the higher eCPM channel to the ads with the lower eCPM channel has a positive effect is to just do it.

I'll have to wait a while before I do this though as I just changed the color background on these ads and don't want to mess with too many variables at the same time.

bgd2006

It sounds like you are still assuming that naming something as a channel has some effect on the ads and earnings in it. It doesn't--the AdSense algo serves up ads based on keywords on individual pages. Channels are a construct that exist solely to help you analyze data. Google pays no attention to it. So if you merged two channels the effect will be to average out the eCPM they were getting, taking into account the relative # of impressions.

The ONLY exception to that is if you are in fact getting ads targeted to that high-earning channel...

You know how to check in your reports for "context" vs. "placement" ad impressions, don't you? If you find that you are getting placement impressions to a significant degree, that might mean the channel is being targeted. But as advertisers can also site target OR keyword target, you can't be sure.

I didn't but now I now know how to check my reports for "context Vs. Placement" and I see your point. I have been under the impression that my channels were getting targeted and that's why one was generating more than the other. Unfortunately the vast amount of the arnings...over 90% are coming from context ads. So I guess I can stop losing sleep if I have my channels set up correctly.

thank you for all the help...very useful in trying to understand AdSense.

The disadvantage to having so many pages covered by one channel is that you can't tell what is making the most money within those pages.

That's why the integration between Analytics and Adsense is extremely important. Analytics will tell you the metrics -- revenue, ECPM, clicks, impressions, CTR -- per PAGE.

So with the Adsense account, you can only see channel information but with the Analytics, you see the pages that bring in the most revenue or ECPM. I was able to isolate my money maker pages from my high performing channels

For example, there's this page created early this year (and buried deep in the archives) with only 2 clicks but brought in $42 in revenue (very very little impressions, too). I need to create more of that page and market the topic more if it can bring in that high of per click revenue!