It's a rare succes for a game like this to increase its playerbase after 1 year. PvP players are notorious locusts.
MO is of course the special breed of sandbox MMO that has quite a loyal core following. But for the game to be growing one year after launch, that is a remarkable development that I only know of EVE and Albion having done before. Now imagine if the game actually delivers the promised content.
Compare with Gloria Victis which launched this year and had far higher Steam concurrency than MO2, and now is quite dead. I bet I am not the only one that tried out GV and now dropped it while still being in MO2.