And lets not forget that the majority apps that start out free...

And lets not forget that the majority apps that start out free and then go to paid subscription DON'T have users continue after the free period. I believe the industry expects 10-20% uptake of the paid subscription, so it not unexpected to hear several examples of people that have done exactly that.

Can we then infer the number of paid subs that WFI has? Unfortunately it involves wild assumptions because we don't know the download numbers and please don't quote my 10-20% figure. I'm just saying the above examples are not unexpected even for a successful app.