You need a system that keeps the players coming back for more and with paid extras that increase the odds of getting more specialized or better content.
I personally don't like Freemium games ... But sadly they do make money. Give you one example: Pocket Pokémon. I play for free ... But at some point in time, I spent $5.00 CAD of real money to get an extra booster pack quicker because I wanted to do so... And had the option of spending $5.00 CAD to get it... And so I did PAY.
But I'm not like this addict that has to get all the cards and pay for all the "extras" like specialized coins, binders, mats, etc. Which some are exclusive to players who PAY to play.
However I am very aware of the CONCEPT ... It's just that I've never ever had the chance or even INTEREST in making such a game. The only game that ever came close to this was "Galactic Frontier" a Star Wars MMORTS which I had developed with the help of another guy who was heavy into playtesting Video Games. We knew nobody in Marketing or Sales ... So the project never went further than to say "No Unsolicited Material" at Lucas Art Games.
So yeah... That's not my niche (making video games mobile or otherwise).
Note #1: Also with regards to the Star Wars MMORTS ... That was just an Introductory Analysis Document which layed out some fundamental blocks in HOW(?) the game could be designed and how the Ladder Rankings would work in a "Soldier" Environment where there would be a ranking officer who would oversee smaller battalions of other "Soldiers".
It was a very COOL concept... But the project never got anywhere because there was nobody to "Champion" the idea (or at least someone who had sufficient connections to make it happen). That's usually what I see ... Is either you need a SMALL TEAM (Programmer, Graphic Artist, Videographer, 3D Modeler, etc.) and a LEADER (CEO/CFO) to help with the raising of funds to make the project a reality (with investment rounds into the product) and some kind of profit sharing scheme or investment ROI...
You put so much thinking on the commercialization of games, that you do not put your time on designing game. You are trying to commercialize something that does not exists. Its like thinking about how you are going to sell the bear skin before even killing the bear.
What problem do you want to solve?
I think you should stick to either selling games, or designing games, but not both. If commercialization is really your passion, publish other people's games. Become a publisher, or kick starter campaign manager, etc.
I did not know that they only made profit on the last boosters. It makes sense.
Not really sure if a lot of money is made from ads in app. I took a look for making you tube videos, and google is really aggressive, it takes like 40-45% of ad revenue. Also recently, companies are not paying as much as before for ads due to the economic recession. It should apply to apps too. (Ads use an auction system, people bids to win ad space).