rotation of in post ads

I notice that authors, editors, site admin and super admin can create a new ad using In Post Ads.
What if any one of us were to create more than one In Post Ad. What happens? Are they rotated?
Is there a way to set it so that the rotation is 50%/50% shared between the author and editor. Likewise, if site admin creates an add, does theirs show up in rotation with any created by the editor &/or the author?

If so, how is different than OIO Publisher?