AdMob mediation with Smart Banners?

[A Tiny Pony]

I'm reading about Smart Banners, as I'm wondering about setting ad type to it (currently "BANNER").

It says: "Note: Most mediation ad networks do not yet support Smart Banners—check with the particular network you plan to use."

However, I can't find that much at the networks I use. 

How does this react if it ISN'T supported by my mediation networks? 

Could that break it, or will it fall back to "BANNER" in some way?

[Eric Leichtenschlag]

It really depends on how the network implemented their adapter. If the smart banner size happens to also be 320x50 (for example on an older phone like a Nexus S), it might return a banner because it understands that size. It might also fall back to banner if the size is close enough. AdMob's general recommendation for adapters is to return no fill if there is no appropriately sized ad from that network to fill the space. In that case, mediation will just try the next network.

Thanks,
Eric