Google made another major change to its Adsense program on Sept 1, 2004. In the past they have required publishers to only have one ad unit per page (even though the TOS has been ambiguous). It now seems that they have mastered the technology to ensure that they do not double serve the same ads across multiple ad units on the same page. Hence Google is now allowing publishers to have upto three ad units per page.

I have tried two ad units on a handful of pages and found that:

- Google fills inventory starting at the ad code it first encounters in a page. So if there isn't enough ad inventory on your topic you may see blanks or PSAs.

- The technology that is supposed to disallow double serving of the same ad within multiple ad units on a page is not 100% up to snuff. You may see the occasional duplicate but publishers can't do much about it.

- If you go with multiple ad units, you should see an increase in impressions and a likely decrease in CTR. Number of clicks would probably go up though at a lower rate than the number of impressions.

- By adding multiple ad units, publishers are showing more ads which means that more ads with lower EPCs are likely to be shown. This would probably decrease the overall EPC seen by publishers.

Overall, I would guess that Google went this route because they have an excess of ad inventory. In a way this is good news for publishers as it means that there are more than enough advertisers. It will take a few more weeks to see what impact this has on publishers and advertisers.

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Thank you for the very good news, Div.

It's timely, since I have recently decided to remove the AdSonar / Quigo ads from my websites (there will be a separate thread explaining why, rest assured).

I have also decided NOT to add any more ads here on GIDForums™ (for members) for the moment. I think for now at least, that "less is more".

...but I can also understand how CPM can drop drastically. They shouldn't calculate impressions by the (ad) units - instead, they should do it by page views.

I also noticed that the more 'expensive' ads appear inside the first ad unit it detects in the markup.

Maybe publishers wanting to display multiple AdSense ads on a page should only consider the "smaller" banner / ad unit sizes like 468x60, 125x125, 234x60, etc. Then, I suspect we'll see much less PSAs on the second (or third) creatives. I've already started seeing some webmasters placing Leaderboard and Tower sized AdSense codes on each web page! Now that's just asking for trouble..

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J de Silva
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I am sure that a lot of webmasters are going to overdo it. And then we also have the usual borderline spammy "scraper" and directory sites that will surely be stuffing more Adsense ads into their pages. These two negatives may lead some advertisers who are already concerned about the low quality of some sites, to finally pull out.

Finally I just wish Google would get rid of the "Ads by Gooooooooooogle" crap they've been using for the last week or so. Very unprofessional and an unnecessary distraction from the actual ads.

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re: "Ads by Goooooooogle"

Frankly, I am not bothered by it. My own AdSense stats have improved since the beginning of the month and I have no idea if it's related to that little change or simply due to the fact that the holidays are behind us.

You're a webmasterworld member, right? So you should know that they (Google) are running this as a test. I'd let them complete the test.

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J de Silva
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I know its a test...but they could have easily done it with some random placements.

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I see your point...

Back to multiple Google ads:

Quickly looking at www.webhost2go.com , I think you should consider replacing the Tower with a 125x125 ad unit in the left column and one 234x60 unit to the bottom of each article, i.e. within the article space.

You can then use the Tower space for other CPM type ads, optionally. What do you think?

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J de Silva
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I would consider adding another unit if I had some half decent traffic.

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