Global market volatility brought the market for new listings to a virtual halt over summer but they are expected to pick up again in the final months of this year.
Previously, Facebook expected to profit from the sale of virtual goods in mobile games, much like how it takes a cut of such sales from desktop games that run atop the social network.
Children involved in the virtual school - known as Notschool - have gone on to get much higher academic qualifications than they had been expected to, said Professor Heppell.