Online sources suggest that Big Fish Games would become one of the first developers to offer subscription based games on the Apple iOS platform.
They are expected to launch their service in the coming days. Users would be able to access multiple games for a fixed monthly subscription of USD 5/7.
A free version supported by advertising is also expected that would feature limited gameplay with time restrictions.
Apple iOS has supported this model for a while now though we have not seen any major player making use of it.
We imagine that the generic customer is interested in paying for games rather than renting them.