Do you think the church will continue to send as many missionaries to places such as Africa and Asia which have relatively higher(though less profitable) conversion rates?

The church really needs Africa for the numbers alone. The retention rate and general problems of church members are no different than anywhere else, but in any part of Christian Africa you can baptise a new-found friend into your religion effortlessly, particularly if it is an "exotic" American and predominantly white religion. While it is like shooting fish in a barrel to baptise in Africa, the Africans lose their concentration just like anywhere else. And when another friend introduces them to another, newer church, then they get re-baptised in to the other church. A whole lot of Africans lose their concentration when attending Mormon churches because it is so damn boring there, when they could be jumping up and down blowing pea whistles and praising God almost anywhere else.