The iTunes app store is an interesting beast. Where some apps take off like a rocket, others crash and burn miserably. This isn't news to anyone. One of the big mysteries (to me at least) is the ad-supported vs. direct-sale models.
At WWDC, I heard talks from many different developers who had generated considerable revenue using the ad-supported model. At the time, I felt it made sense to attempt a free version of Mayan Madness that would increase the visibility of the paid version and hopefully generate some revenue in its own right.
We chose Mobclix as the vehicle to move us in this direction. That decision was regrettable given it was based on Mobclix claiming to have no pay-out minimums and we have yet to see a single penny from them.
Unfortunately, things didn't work out as expected. The ad revenue generated was pathetic even compared to our other free app, Eenie Meenie. Furthermore, there is an interesting psychology that occurs on the app store where people's perceived value of an app is less if it's free. This is easily observed in the many free apps that have terrible reviews compared to their paid counterparts.
So, Mayan Madness Free found itself in a situation where it wasn't generating any revenue, garnering app store reviews that were more negative than the paid version and, of course, cannibalizing sales of Mayan Madness. One can argue that not having a lite version may also hurt sales of the paid version but I've directly observed several situations where a user that would have paid for the app opted to download the free version instead and found no incentive to purchase given the games were identical.
All of these things drove the decision to remove Mayan Madness Free from the app store. We'll continue to support and enhance the paid version. And, who knows, maybe a model will become obvious where Mayan Madness Free can re-emerge as something successful.