Google Adsense quietly launched a new 320×100 ad unit, targeted as a large mobile banner to display a single ad which will fit well in smartphone screens. The size seems to be a great fit for smartphone screen sizes and will definitely enhance the ad performance. As I was trying to create a new ad unit, this size became visible and is a new addition.
Adsense Large Mobile Ad
We use the responsive Adsense ads which change size depending on the screen resolutions. This is a good move as you can display effective ad sizes which will fit the screen and match your responsive web design. If you use too large ad units, they might cause significant horizontal scrolling or cause large blank spaces on mobile devices while the ad unit loads.
We use the 336×280 ad units (know why they are better than 330×250) and they swtich to the smaller 300×250 rectangle on smaller screens. But the unit is still large and occupies a lot of space, and by the time it loads, user have already scrolled through the blank space or are confused about the large banner size masking the content.
320×100 Adsense Banner
See how this ad unit looks like .. if you are using a mobile browser on your smartphone to view this post, probably you are already seeing these ads only.
I think this 320×100 ad size is super and much better than the earlier attempt at mobile ad sizes. The text fills very well and I expect a good CTR, though I did not see any image ads competing for this ad size (Probably there is not enough inventory for it as it is not a standard ad size). So we have started using it to replace the large rectangle ad in our responsive ad unit.
The only problem is that there are many small mobile screen sizes which are even smaller than 320px, and for those small screens this ad unit still scrolls horizontally. Probably an even smaller ad unit can be fitted there like the half banner (234×60) or maybe square ad units. Use this ad size … it will work well.