Advertising pop window in game?

Hello :-)

I've seen some games (not sure if made with Unity or not) that have advertisements that pop up a window the user must close to continue.

Anyone know if this is possible with a Unity game?

More specifically with Unity 3.5.7 game developed for iOS.

Currently trying iOS SDK Pro from asset store but not looking like it will do that.

Thanks!

Here is an example of a game I just played with the pop up I want to use.