Very happy for this one. Because it could have just as well sold as 'little' as P3 and P4, which would have been fine. But I was always sure that more people would be into this series if they just gave it a chance.
I attribute much of this growth to the eye-catching presentation of the game.
They did go all-in on the presentation, but Sega also marketed the hell out of it compared to previous entries (and other Atlus IPs).
Having half a dozen Persona spin-offs also helped the series visibility.
I hope this translates in more quality releases from Atlus.