OK maybe I wasn't making myself very clear in the first two posts?
What I am suggesting is allowing licensed game developers to include 3rd party ads in their games in the Scirra arcade so they can make some revenue.
That would be a big selling point for Scirra to promote getting a licensed version of C2 or C3 and game developers are more likely to get a licensed version if they also can make some revenue from the Scirra arcade to offset the cost of the license.
It would not cost Scirra anything to allow that and they can charge a small monthly fee of around $10 a month for licensed developers that want to have that perk in their games so it makes Scirra ongoing revenue. If Scirra wants to allow that for free even better but I think most game developers myself included would happily pay $10 a month to be allowed to include 3rd party ads in our Scirra arcade games.
So you are providing incentive for people to get a licensed version and making revenue from that perk and you will get many more game developers to get a license if they see they can offset the cost of the license with games in the arcade.
I really do not see any downside of doing this for Scirra?
Maybe Tom or some of the Mods here can tell me why that is a bad idea or what the conflict is that Ashley seems to feel is a negative of doing that with the arcade?
ADDED: You might look at ICHIO which is using a format like I described with both free games and games that can be downloaded or includes advertising.