if its free to play, then, you have to pay to upgrade then its a misnomer; it cant be free to play.
its like the Park is free to enter, but, you have to pay to go on the rides.
its an inducement, carrot and stick.
they have to make money - they'll not give it away - it will not be free.
the use of those words is misleading - they set you up to believe something that is not entirely true. the seed is planted and soon demands water. etc etc....
