http://www.pcgamer.com/fortnite-battle-royale-claims-more-than-ten-million-players/

Last week, Epic announced that Fortnite, it's multiformat game of building and defending bases, had amassed more than seven million players. Today it claimed an even meatier figure, saying that the standalone Fortnite Battle Royale mode has pushed past ten million players, all by itself, since its debut two weeks ago. 

"Ten million players" isn't the most precise measure, and Fortnite isn't on Steam so it's impossible to verify the figure, although I can't imagine that Epic would throw it around if it wasn't accurate. But what's really interesting is that it's specific to Fortnite Battle Royale: I assumed that last week's player count was driven largely by the Battle Royale mode, but this would indicate that it's almost all coming from that direction.