I didn't follow the development of Overwatch, so I wasn't all that hyped when it was released. When I first bought the game, it was because all my friends were raving about it and I wanted to see what they were talking about. I liked a lot of the character designs and the way it continually rewarded you for playing, so I kept playing it occasionally. Yet, I never felt compelled to improve or play if I wasn't grouping up with friends. Then I discovered Blizzard's Overwatch shorts.
Blizzard may cop a lot of flak for their storytelling in other games, but their somewhat cheesy style really worked well in Overwatch. The production in each short was amazing, and they immediately made me want to read more about the lore. As I read, it changed the way I thought about and played the game.
In my opinion, the effort Blizzard is putting into the storytelling in Overwatch gives it an edge over other popular online multiplayer games. Each character has an interesting backstory and personality, and the subtle hints you get from the in-game interactions and tiny details in each map are a very nice touch. However, Blizzard didn't stop at mere backstory—there's also the promise of more story content to come. The Sombra ARG is a great example, despite all the criticism it's got recently. There is some great fan content to be found as well, some of which Blizzard is even incorporating into the game and lore. It creates this great sense of developers and fans building the world of Overwatch together.
When I play the game now, I feel really invested in the characters. When I do well with my favourite characters, I feel like I've done them justice. My aim might be less-than-stellar, but I feel compelled to practice and improve because I don't just like playing the characters, I love the characters themselves.
Goes to show that a little attention to storytelling can go a long way.