For anyone confused, a "mediation platform" here means a way of putting adverts in your games.
In July the game-making software project unity3d was bought by the advertising company "Iron Source".
Now the combined company will charge the game-studios that use Unity money, for every time their users install a game, even a free one - unless they also agree to use the Unity/IronSource advertising platform.
I was just worried they might put adverts in my freeware, but I suppose charging me for not having them is similar.
@d12926de