The number of smartphones being used worldwide topped one billion in the third quarter, according to the U.S. Strategy Analytics consultancy firm. That number could double again in less than three years. Investors in Nokia, though, may have forgotten that they are engaged in a growth industry. On Thursday, the Finnish device maker unveiled another substantial operating loss – €580-million ($747-million) on a reported basis in the three months to September – while its sales fell by one-fifth from year-ago levels. Again, too, there was an air of nervous water-treading: the group’s new Windows-based Lumia phones start shipping next month, so, come 2013, the market may finally be able to assess whether Nokia/Microsoft can establish a viable sector position.