How long do iAd apps take to start generating impressions?

Question

I released an app with an iAd in it on Friday. So far it has generated zero impressions with many requests - a fill rate of zero. Most of my requests are in the USA (~90%) so the problem is not that the requests are from countries which iAd does not support).

An older app of mine which is less popular is consistently generating a 98% fill rate despite a lower number of requests.

I was just wondering if it's normal for iAd apps to not generate impressions right away. Should I expect to eventually get impressions after some time, or is something wrong?

Answer 1

It takes 1-4 days for an app to start receiving ads. It's normal¹ for the fill rate to be zero or nearly zero for a few days after release.

_{1: This is not documented on Apple's website anywhere, but Apple iAd representatives confirmed this via email.}