Conversion on anything trial-like, is going to be very small, and likely worse than even an upfront purchase because you will hit some people who are satiated with a small amount of trial gameplay or people who decide not to buy after playing.
Keep in mind that the best premium apps have lifetime revenues in the low tens of millions, and the best F2P are in the billions.
Keep in mind that the best premium apps have lifetime revenues in the low tens of millions, and the best F2P are in the billions.