Same Admob ad unit ID for different apps?

Question

Context

We are trying to integrate admob inside our Apps, we have 25 apps which are mainly livewallpapers.

When we created an ad un

Answer 1

I can only partly answer your questions:
You can use one unit ID (which is assigned to any of your apps) in all your apps. But in my opinion, this is a very bad idea. Why. Because it produces fake statistics (the one app listed in AdMob shows all advertisting statistics of all apps). In the end, you will not even see how to optimize your earnings because you don't know which app causes lots of earnings and which one does not. (e.g. If one apps causes no earnings you could place your ad somewhere else within the app). So one unit id per app would be a good solution.

I can't answer question 2, because I never thought about something and I suggest to reconsider your intention because too much ads will annoy the user and you will not earn more because the user will surely not click twice just because you use two banners. He probably won't click because it annoys him. And I'm not even sure if there are different ads showing at the same time.