Most popular ad creative sizes are 320x50, 300x250, 320x480 for mobile phones and 728x90 for tablet.
Full distribution of creative ad unit sizes:
Why 320x50 over 300x250?
- Inventory, 62% of GroundTruth's inventory is made up of 320x50. 17% only is 300x250.
Why is there less inventory available for this size?
- Publishers stick to smaller standard ad sizes because bigger size ad units can interfere with the user experience on mobile app or website. Additionally, because the ad unit is bigger, it is more likely that the clicks generated from the 300x250 ad are accidental and therefore yield an inflated CTR.
Are there separate dimensions for retina screens?
- GroundTruth accepts creative sizes for newer phone screens. iPhone 6 and above, for example.
- Simply double the dimension of each ad unit, and upload into Ads Manager. e.g. Retina version of 320x50 is 640x100.
- Ads Manager will automatically serve the correct version depending on the phone or tablet screen.