's answer about the high churn on OF. Giving access to the whole archive the first month is definitely something that hurts their churn rate a lot. I wonder if they are aware of this issue?
It's possible churn rate doesn't hurt overall revenue; a churn dude might be more likely to spend a month subscription once on a bunch of diff girls, and a non-churn dude spends the same money on one girl. It's possible eliminating archive access wouldn't help.