Possibly the highest praise I can give for The Old Republic is that BioWare has managed to successfully transition from being a dominant force in the realm of single-player RPGs, broadening in both size and scope to bring that same great storytelling experience to a much larger audience. In most cases this transition has been executed flawlessly, marking SWTOR as the first MMO where story actually matters. Yet it also neatly bookends the gameplay template we’ve all grown accustomed to over the past dozen years rather than attempting to establish the next great chapter in the MMO history books.
One thing is absolutely indisputable - Star Wars: The Old Republic hit the MMO subscriber market at the place where it's particularly fragile these days - story. And it's not just marketing - BioWare's strength happens to be story, and the game delivers. Whereas other MMOs might keep you playing till 4am to finish a quest, a level, or get an epic piece of equipment, you might just find yourself late for work because you wanted to see how a particular story arc pans out.