I have a AdMob ad in a \"dialog\" (a View I created to look like one, because ads will not fit in a normal Dialog) in my app. Usually it takes about 4 or 5 seconds before th
I have done it by use one adview multiple time and in multiple activity
It just load once, and you can use it where ever you want,
It will refresh on its given refresh rate.
demo is given here
you may need some modification but actual idea is implemented.