True Story: Adding more 300×250 units can save your life (And Other Best Performing Ad Units for Your Site)

As someone on the publishing side, I feel compelled to share a story, especially to those other pubs out there who are (1) considering placing ads on their sites for the first time, (2) going through a site redesign, or (3) wanting to shake up their ad setup a bit. 

Once upon a time, one of our publishers decided to redesign his site. He agreed to remove a few ad units and added some different ones. The number of ads per page did not change. In fact, in some cases it went down from 3 to 2 ads. Immediately after launch, his ad revenue nearly doubled without much traffic increase. It sounds magical, doesn’t it?

Here’s what happened: before the redesign, the site had mainly 728×90* units, most of which were below the fold (BTF – meaning, the user must scroll down to view the ad). They did have a few 300x250s scattered around, but not nearly as many as the 728x90s, which were dominating the site.

Post-redesign: all 728×90 units were removed, replaced by 300×250 above the fold units (ATF – appearing at page load before scroll down). They also added 160×600 BTF units. Now the site only has 2 units per page. Again, I must restate, they did not experience a significant increase in traffic, yet ad revenue nearly doubled.

Why would this happen? Is it possible for ad revenue to increase by actually removing an ad unit? Did the publisher bewitch the market into giving it more money? The answer is simple: the 300×250 is one of the best performing units in the market. By tripling the number of 300x250s and removing the 728×90 units, the site’s ad setup became much more valuable.

Additionally, placement matters. The new 300×250 units were placed not only above the fold, but also directly next to the site’s content. User eyeballs can easily shift over a few centimeters to the right to view the ad. The 160×600 was also optimally placed. Even though it is below the fold, it still gets viewed because it is also located right next to the content, content that users must scroll down to read. This almost always guarantees that the ad will be viewed, and there is a higher probability that they will get clicked on. Music to an advertiser’s ear.

In contrast, the 728×90 units, though they do have the capability to perform well, are not so easily viewed or clicked on. They tend to get ignored because users more often skip right down to the content. Moreover, a 728×90 BTF unit may be one of the worst performing units because users often don’t make it all the way to the bottom of the page. They have a high chance of – here comes the advertiser’s worst nightmare – never even coming into view.

We’ve seen this trend on all of the sites we manage – the more 300×250 units, the better the revenue is. That’s why, when giving advice on website design, we always recommend the friendly little box unit that can be powerful enough to steer your revenue for the best.

CAUTION! Before you go sprinkling your site with too many 300x250s, it’s important to remember that cannibalism can and will occur. Cannibalism?? What??? If you’re picturing little banner ads chomping away at each other Hannibal-style, it’s actually not too far from the truth. Placing too many of the same type of ad units on a site will dilute the value of that unit. It follows basic supply and demand rules: the less there is of something, the more everyone wants it. It’s okay to place more than one 300×250 unit on your site, but you should definitely test performance to make sure you’re hitting those high CPMs.

publisher content


In case you want some other suggestions, below is a chart of ad units and their average corresponding click-through rates (CTR).** Though not necessarily a requirement for great performance, strong CTRs typically yield better CPMs and hence, higher revenue. You may also want to play around with “dynamic” units – allowing one ad size (let’s say a 300×250) to shift into a 336×280 or 300×600, so you have the option of serving multiple types of excellent performing ads. Happy learning!

banner CTRs

Source: “The Best Performing Banner Sizes for AdSense” (February 19, 2014) by Amit Agarwal. From (, retrieved April 9, 2014.

* If you’re unfamiliar with these ad sizes (and so you don’t think I’m throwing around random numbers), here’s a helpful Wikipedia post that sums them up nicely, as well as provides you with a friendly illustration.
**Please keep in mind the “Medium Rectangle” labeled above is another term for the 300×250 unit.

13 Comments to True Story: Adding more 300×250 units can save your life (And Other Best Performing Ad Units for Your Site)

  1. Amazing experimentation with adsense and yes whatever you have mentioned is true like on one of my blog I was using 728*90 leaderboard and the clicks were horrible so I sifted them back to large or medium rectangle which are indeed best performing ad units

  2. Great article. I just started plaing with adsense. Any advice how far apart those adsense units should be from eachother?

    • I don’t believe there is a specific correct answer for the amount of spacing between an ad unit. That said, you should make sure not to stack one ad on top of another and at least put a small content buffer between them. Ideally, this would be actual content to avoid ‘stacked ads’.

  3. Actually on my website 728×90 ads are having high CTR but the CPC rate is to low as 0.03 to 0.08$. and this ad unit is optimal for my site so how can i increase CPC rate? i had tried blocking of categories and reviews also blocked for various low cost paid site. but since my CPC is very low.

  4. I too have been experimenting with different adunits. Now I can see that the 300 by 250 is one of the best ad unit. It is performs more better when place close to the content. I have also decided to use 2 ad units. My earnings is always high with that but Clicks are low. Can you explain why it is so?

    • Hey John,

      Thanks for the comment. The truth is that the answer to what you’re asking (300×250 vs 300×600) will vary based on the exchange you’re working with and your site layout. In general, I’d advise a 300×600 to be used in conjunction with a 300×250 in a spot on your page that could support both. When you setup the invocation code from DFP, include both a 300×250 and 300×600 as a size capable unit and then you can run both.


  5. Hello

    Can any one tell which banner size make more money. medium 300×250 rectangle or large 336×280 rectangle. which size most companies prefer.



  6. i build my premium template where optimized to show adsense ads, 300×250 ads is more often showing up for below 1280px, it’s hard to view thats size for 1280px above device screen, is adsense more targeting 300×250 ads for tablet users and mobile, for 43366px width screen always showing leaderboard 728×90, it seem this one targeting tablet and pc users. i am still need to learn how it does advertising strategy.

Leave a Reply

Your email address will not be published. Required fields are marked *