Hello
I know I wrote an article about
in which I said that it is a known fact that the first AdSense Ad Unit in the HTML receives the highest paying Ads.
However reviewing my AdSense statistics today after replacing my Large Rectangles in my content with medium rectangles I am not that sure anymore. Or at least the theses needs an additional comment.
I still think that the highest paying Ads are served in the first Ad Unit that appears in your HTML. However this does not necessarily mean that the highest paying Ads are shown in the first Ad Unit. I think this effect depends on your Ad Unit sizes and if you allow image Ads or not.
First Some Statistics
My first AdSense Ad Unit (visible and in HTML) on my forum is a Large Rectangle serving image and text Ads.
My second AdSense Ad Unit (visible and in HTML) on my forum is a Medium Rectangle serving image and text Ads (switched from a Large Rectangle a few days ago).
Now comparing the combined stats of those two Ad Units (to list them on the detailed level I track them would be too much work :p)
- The CTR of my medium rectangle (which is the second Ad Unit) is 118% higher
than the CTR for my large rectangle (which is the first Ad Unit). - The eCPM of my medium rectangle is 165% higher
than the eCPM for my large rectangle.
The average CPC is 138% higher for my medium rectangle then the CPC for my large rectangle.
But how can that be if my medium rectangle is the second Ad Unit on
my page and the highest paying Ads are served in the first Ad Unit?
Let me explain my theory
Each Advertiser creates different advertising creatives (Banners) in different sizes
for his campaigns. Most of them will use Ad sizes that are industry standard which are:
- 300 x 250 – (Medium Rectangle)
- 180 x 150 – (Rectangle)
- 160 x 600 – (Wide Skyscraper)
- 728 x 90 – (Leaderboard)
This only applies to image Ads and RichMedia Ads. Ads which all have a defined size.
Text Ads are independent from the size of the Ad Unit they are displayed in.
So what does this mean?
It means that depending on the Ad Unit sizes you use on your website different
contingents of Ads to display are available.
So let’s do a simple example:
Let’s take one webpage of a website using my Ad Units setup I described above.
Large Rectangle format:
- 20 Advertisers created an image Ad for that Ad Size and
they compete with 100 text ad Advertisers for this Ad spot. - 120 Advertisers are now competing for this Ad Spot
Medium Rectangle:
- because this is industry standard Ad size 150 Advertisers created an Image Ad
for this Ad Size and they compete with 100 text ad Advertisers for this Ad spot. - 250 Advertisers are now competing for this Ad Spot
And because Google AdSense is auctioning the display of Ads for each Ad Unit in real time more competition means higher CPC which translates to higher eCPM for you as publisher.
This means the more ads that are available for an Ad Unit the higher your eCPM.
By enabling image Ads as well as text Ads for your Ad Units you increase the competition for your Ad Unit and with this your eCPM.
By choosing industry standard Ad Unit sizes you increase competition because more Creatives (Banners) are available for these sizes then for non standard Ad Unit sizes and with this you increase your eCPM.
This is the only way I can explain the discrepancy I see in my AdSense Stats without discarding the well known fact that the first Ad Unit gets the highest paying Ads.
Conclusion
Enabling Image Ads (at least for industry standard Ad Unit sizes) is important to
increase your revenue.
And only if you compare Ad Units of the same size or text only Ads then the fact is true that the first Ad Unit gets the highest paying Ads.
What are your thoughts on this?
Do you notice the same when checking your AdSense statistics?
It just came to me that I could compare older stats of my site from a time where I used a large rectangle on both of my Ad Spots I talked about above.
The results are:
The CTR of my 2nd large rectangle was 105% of the CTR
of my 1st large rectangle.
The average CPC of my 2nd large rectangle was 113% of the CTR of my 1st large rectangle.
The eCPM of my 2nd large rectangle was 120% of the eCPM
of my 1st large rectangle.
This can't be explained by different contingents of Ads being available due to the different Ad Sizes and both Ad Units had Image Ads enabled.
Even though I still stand by my conclusion and explanation of my theory I think the thesis needs another addition.
The only reason for this discrepancy I can now think of is the influence from placement targeting showing its effect. Maybe the 2nd Ad Unit was more often placement targeted then my first Ad Unit even though I can't really believe that.
But currently I don't know what to think anymore.
Does this mean Google decides which Ad Unit gets the highest paying Ads on totally different criteria then we thought it would?
One thing I am thinking is that a factor that is influencing which ad will appear were is the proximity of keywords, and the weight of those (is it a <h1>, <h3>, <strong> tag?).
High paying campaigns aiming for specific keywords might place an ad in the last block on your page just because there happens to be a <h3> tag with the desired keyword right next to it.
Greetings.
They usually have a much lower conversion rate because they require two clicks.
So I don't think that implementing Link Units will have an effect on Ad Unit CPC
even though this is just an educated guess.
I too have noticed the phenomenon of the ad that appears lower on the page, performing better. In my case, this is not on a forum but on a wordpress website.
I have read that viewers get to the end of the information/article/text and then think "now what" and look for something to click - so I have been placing a large rectangle at the foot of the page.
I tried adding a video at the very foot of some pages with the advert between the header for the video and the video itself so that the ad was in view whilst the person was watching the video. Ctr is better for these ads.
As I only joined this forum yesterday, I just wanted to say a huge "thank you" to you admin for the tips on Adsense placement that I "devoured" yesterday!
I implemented some changes, and have just checked my earnings this morning - yesterday was my best ever day!