Google Ad Manager Desktop Expandable Ads
First Image URl :
Size should be 728x90 of the Image
Second Image URl :
Size should be between 728x100 to 728x500 of the Image
Second Image Height :
Don't enter above 500.
Take a peek how the final creative will look on the page
How To Traffic Expandable Ads On DFP Desktop
Insert Macros For Click Tracking!
Create an ad unit of size 728x90px
Create a new or select an exsiting order
Create a new line item and enter expexted creative size as 728x90
Choose any lineitem you wish to deliver this ad on (don't use AdX & AdSense) & hit Save
Upload above code in the third party code creative and hit save.
Implement the ad unit normally