Hmmm well that was part of their marketing they decided to do because of lack of budget for it. Bluehole went with Twitch streamers. And on PC where it was a paid title since release it has sold really well I can't see why them giving it away should discount its success.I just feel weird counting a game that launched on ps+. They gave it away like candy that first month.
Main point being the game's growth hasn't slowed down one bit since it launched it sales has not decreased month on month and it's stayed in PS4 Digital charts(Both NA/EU) for long periods of time.
Retail wise for example in UK the above is also true.