Problems with passback tags & multiple ad unit sizes

Published by: Elise Boyd ,
Published on: May 26, 2014

Hi guys,
Our site has exclusive partnership in certain countries, so we have an order in DFP SB that delivers 100% sponsorship of their passback tags. They then set up orders on their end, falling back to our remnant tags.
A lot of our ad units are set up for multiple sizes, which we've had absolutely no trouble with when we traffic ads from our end.

Our set up is as follows (truncated for brevity):
slot1 = googletag.defineSlot('/xxx/xxx', [[300,250],[300,600]], 'div-gpt-ad-xxx-30').addService(googletag.pubads()).setTargeting("Category", "xxx");

googletag.defineSlot('/xxx/xxx', [[970,90],[970,250]], 'div-gpt-ad-xxx-18').addService(googletag.pubads()).setTargeting("Category", "xxx");


The issue is when our partner tries to serve one a creative to one of the optional sizes. E.g. when they serve a 300x600, it cuts off to 300x250. If they serve a 970x250, it cuts off to 970x90.

I think it's because when we've set up the passback tags on our side, DFP SB requires you to define what size the creative is. So, we have a 300x250 creative which delivers the passback tag. So, DFP has no concept of what size the creative actually is when it gets passed in.

Hopefully that makes sense! Any help would be greatly appreciated :)


Hi Elise,

I've actually had to deal with this exact scenario.

Unfortunately I don't think there's any 100% foolproof means to do this given your current setup. It might be possible for your partner to include some custom JavaScript when they traffic creatives in their DFP account which detects the size of the IFRAME it is in and resizes it. This sounds error prone to me though.

One solution is to switch to synchronous rendering and disable SRA. This way, ad tags will NOT be loaded into an IFRAME, and so the size you configured in DFP will not be enforced. Your partner should be able to traffic any size ads with no trouble since there will be nothing to constrain them.

Sync mode is slightly slower than async/SRA, so you'll have to decide if the performance hit is acceptable.

Rocket Fuel