300x250 versus 336x280

[Ironside]

Has anybody got an opinion on which of these ad units will work the best? My bottom ad units using the 336 have been top earning units for a while now. However, I haven't tried the 300 units, I'll just wondering what people thought and if they would work better?

[netmeg]

Our experience is not going to be your experience. If you want to know how it would perform on YOUR site, you need to test.

[Ironside]

I was simply asking for people's experiences using both units. After all, Google seem to think they know what's best for my website, I am forever getting messages from them telling me that I'm missing out because I haven't done this or haven't done that.

[bhukkel]

A couple of weeks ago Google announced it is showing smaller size ads if the cpc is higher. If i look at my site, sometimes a 300x250 is showed instead of the larger one.

So in my opinion just show the larger one and let Google do the thinking...

[ken_b]

So in my opinion just show the larger one and let Google do the thinking...

Yup, that's my opinion too.

[Ironside]

I read conflicting reports on different places regarding how your ads should be shown. Some sources state that image only ads pay the best, other sources state you should show text and image ads, whilst you will find another information source saying that you should only use text ads. But like you said, the only reliable way is to test your ads on your website and see how you get on.

[nomis5]

One site has good results with 336 sized ads. Another site has far better results with 300 sized ads.

It totally depends on the site which size works best.

[Swanny007]

336 works on some locations on some of my sites and the 300 works better in other spots. Do an A/B test on both sizes for 2 weeks and see which has a higher RPM.

Oddly enough, I did test 336 vs 300 after Google announced they backfill the 336 ad with 300 ads, and the 300 ad performed better (RPM), so I went with the 300 size. Overall though just putting in the 336 is the way to go if it fits with the site's design.

[JCKline]

I use both on one page because they fit well with my sites, and usually perform well.

[jimbanks]

As a publisher there are many more advertisers who opt for the 300x250 so you might find there is more competition for the inventory which might lead to higher CPC's which leads to higher revenue.

Is this on the basis for which you might make most money from?

Size is less important as placement on the page, blending of the ad units into the content and other factors.

As an advertiser there are greater opportunities to capitalise on 336x280 ad units, that tends to be the size I look for the most on the Ad Planner.

Don't forget the technical name for the 300 x 250 is MPU, which is multi-purpose unit, it is the size that you can fit text, image, flash, video ads in.

[nomis5]

A couple of weeks ago Google announced it is showing smaller size ads if the cpc is higher. If i look at my site, sometimes a 300x250 is showed instead of the larger one.

I just noticed this as well. Anyone know where G mentioned that they would do this?

[bhukkel]

@nomis5

See adsense blog
[adsense.blogspot.nl...]

[jpch]

I choose not to go with the 336x280 because when they show a 300x250 it is centered. It's going to look weird in my sidebar because everything else is left aligned.