what's the deal with single ads in the 336x280's?

The 336x280 text units typically display 2 or 3 ads. But I've recently been getting one single big text ad in that space. What are these?

I don't mind only displaying one ad instead of three, but for they never match my site content. It's weird stuff like chemotherapy drugs and The Economist magazine.

 

I do not see the untargeted ads that you mention. Just too much white.

However, regarding the 336 ads, although Google says the reduced number of ads results in higher CTR, I think the 1 or 2 ads look spammy, due to their undue emphasis.

Yes, I want to maximize my CTR. But at what price? By throwing aesthetics out the window? No. So I have been replacing 336x280s with 250x250s.
You can still have the same problem, but at least you reduce the overbearing spammy white space by 30 pixels. My personal preference would be a 336 wide by 200 tall that ALWAYS has 3 ads in it. Just my thought.

For those of us perfectionists that like "the looks" of things, it would be nice to be able to click on a box called "Fill the Ad Block?" I would click "Yes".
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Why not try the new 200 x 200 px size? I've found out that they're really easy to blend (example) and have a nice CTR (> 15%/block sometimes)

 

There is a reason why beeweb is getting a single ad or none like you, the page needs more content and keywords to get relevant advertising displayed.

 

I believe you mean Flip, I do not have those problems at all.

 

If you are seeing just a single ad in the entire unit, it could be a CPM based text ad.

 

Yeah if its a single ad with larger font then it means the advertiser has specifically selected your url to advertise on.

This is generally a good thing, ive never experienced them though.

 

Generally, if they find an ad that would match all of it, or they think will work very well they will show one and emphasize it.

 

usually big ads appear if the advertise has target his ads to your site.