Recommended Mobile Web ad sizes
The reason is that Mobile Web are regular websites viewed thru a browser and websites that are not optimized for Mobile Web do not offer 300x50.
The 320x50 banner is used for InApp advertising.
| Ad size | Description | Desktop & Mobile web* | Mobile apps* |
|---|---|---|---|
| 300x250 | Also known as a medium rectangle. Tends to have more ad inventory available from advertisers, which can increase earnings when both text and image ads are enabled. Performs well when embedded within text content or at the end of articles. |
✓ | ✓ |
| 728x90 | Also known as a leaderboard. Tends to have more ad inventory available from advertisers, which can increase earnings when both text and image ads are enabled. Performs well if placed above main content, and on forum sites. Can also be used with tablet-optimized pages. |
✓ | |
| 160x600 | Also known as a wide skyscraper. Tends to have more ad inventory available from advertisers, which can increase earnings when both text and image ads are enabled. Best if used along sidebars of webpages. |
✓ | |
| POP | Mobile Pop-up A pop-up appears on the main browser window The pop-up is a full screen ad that displays directly the landing page |
✓ | ✓ |