Welcome to WebmasterWorld Guest from

Forum Moderators: incrediBILL & martinibuster

Message Too Old, No Replies

Sudden drop in CTR, but I "know" why.

I just don't "understand" why.

4:31 pm on Nov 19, 2005 (gmt 0)

Full Member

10+ Year Member

joined:June 27, 2001
votes: 0

After playing around with channels and changing the color and placement of the ads on my site, I finally found the best way to use them. I have left them unchanged in this best performing position for a few weeks now. The CTR has consistently been almost exactly the same every day since.

That was until 2 days ago, when for no reason that I could figure out at the time, the CTR dropped about 3 points. At first I had no idea why, but now I think I may have figured it out.

There are 2 ad units on most of the pages of my site. One is a skyscraper which is the 4 boxes of text on top of each other, and the other is the banner, with 2 boxes of text side by side.

After looking at the pages of my site, there are very rarely any boxes of text anymore. Instead, for example, the skyscraper is showing just one really long ad, and the banner is showing 1 wide ad.

I think this is effecting my site's CTR, and I'm wondering why the ads are showing like this all of a sudden, and, if possible, how to fix it?

Thanks in advance for any help.

4:51 pm on Nov 19, 2005 (gmt 0)

Preferred Member from US 

10+ Year Member

joined:Nov 13, 2005
votes: 0

i think what you're describing is situation where Google doesn't have enough ad for your content. in that case, Google with massacre the ad block by displaying just one to two ads. I'd suggest going to an ad format where, in combination of one ad block or more, you display no more than the number of ads Google can deliver.

for example, if for your 'red widgets' topic on a page Google can only display 3 ads, use one 250x250 block, or two small blocks.

hope this helps.

5:16 pm on Nov 19, 2005 (gmt 0)

Junior Member

10+ Year Member

joined:July 11, 2004
votes: 0

is it a high traffic page?

maybe google is trying CPM ads on that page? Those big ads that fills the unit are CPM ads. Did you notice whether they are commercial or non profit ads?

wait & watch. google may optimize & revert back to text ads.

part of the game!

5:26 pm on Nov 19, 2005 (gmt 0)

Full Member

10+ Year Member

joined:June 27, 2001
votes: 0

mlalex, yes, these big ads that fill the entire unit seem to be showing up on the most viewed pages of my site. And yes, the ads are commercial. They are not public service.

So then if Google IS trying out CPM ads on my site like you mentioned, is this something I should be happy about?

5:56 pm on Nov 19, 2005 (gmt 0)

Preferred Member

10+ Year Member

joined:July 26, 2005
votes: 0

Actually google stopped displaying fixed number of ads a few months back. They now mix and match ads in each box placement in order to try and provide the highest level of income.

If you get a single large ad in a block, it is because google believes between its payout rate and its ctr it is the most valuable ad to have in that place. Above and beyond any other ads for that segment.

The intent is to maximize dollars. You mentioned CTR but you didn't mention revenue. What was the change in revenue. I have seen this mechanisms and they are far from perfect, so you may see a decrease even if the intent is an increase in revenue. That being said if various advertisers moved out of your market it can shift things around a great deal and change up your revenue substantially.

6:33 pm on Nov 19, 2005 (gmt 0)

Junior Member

10+ Year Member

joined:July 28, 2003
votes: 0

There is a possible interaction between skyscrapers and the single large ad showing there. If you have the sky starting above the fold but well down the page, the single centered ad may be mostly or completely below the fold.

If this may be happening to you (on small browser windows -- not necessarily _your_ browser window), you might consider swapping it for the vertical banner (120x240, I think) so that the single ad is forced to remain above the fold.


7:18 pm on Nov 19, 2005 (gmt 0)

Inactive Member
Account Expired


aeiouy is right. Those are probably NOT CPM ads, nor is there necessarily a problem with ad inventory.

Those are what Google calls "expanded" ads, plain old text CPC ads, expanded to take up more space. The algorithm does it when they think it will bring in more income than showing more ads would--I'm guessing that the ads or ads that are chosen must have a history of a higher CTR or have a better bid value.

I see them all over my site too, and don't think they are working very well. I'm just waiting it out--Google will give up on them if they don't work.

If you really hate them, here's a tip. I only see these in horizontal-format ads. Never in the narrow skyscraper format I use on much of my site. Try different formats and see what happens.

8:33 pm on Nov 19, 2005 (gmt 0)

Full Member

10+ Year Member

joined:June 27, 2001
votes: 0

hunderdown, actually I'm seeing them in both formats, and they are not performing well at all for me.

In the case of the skyscraper, there is now 1 ad showing where there used to be 4. That's 3 less chances of getting a click. Not to mention, it's the format the of ads - those little boxes of text - that I think people find very appealing. One long/wide ad does not have nearly the same effect.

That would have just been my opinion before, but now I have statistical proof.


5:28 am on Nov 20, 2005 (gmt 0)

Inactive Member
Account Expired


Darn. I was hoping they didn't show up in vertical formats.

I'm going to watch this. And may email Google about this. you should do the same. The more they hear from publishers about this, the more likely it is they will drop this "feature."

5:39 am on Nov 20, 2005 (gmt 0)

Senior Member

WebmasterWorld Senior Member 10+ Year Member

joined:Mar 1, 2004
votes: 0

I've got definitely one advertiser and I strongly suspect two others as well that are targeting my main site. I have seen all 3 of these advertisers in every size of adblock that I have tried: Leaderboards, banners, skyscrapers and large & medium rectangles. The only way that I have found to have a decent selection of ads without adding them to my filter list is to have the maximum of three adblocks on a page.
6:25 am on Nov 20, 2005 (gmt 0)

Moderator This Forum from US 

WebmasterWorld Administrator martinibuster is a WebmasterWorld Top Contributor of All Time 10+ Year Member Top Contributors Of The Month

joined:Apr 13, 2002
votes: 327

If you're seeing it in multiple places, it could be a CPM ad.

I do a bit of CPM bidding myself through adwords, bottom feeding click throughs at a $0.25 CPM on competitor sites to feed them to my own sites.

I'm using a mix of text ads and banner ads. I suspect my competitors make more on $0.25 CPM than they do on clicks.

I also run CPM ads for a client, and they only show up in certain parts of a site (unless I bump up the CPM to two bucks, in which case it receives tens of thousands of impressions every day).


Join The Conversation

Moderators and Top Contributors

Hot Threads This Week

Featured Threads

Free SEO Tools

Hire Expert Members