Ed gets a message of his own at the end when he figures out that his life can be more than what it's been so far. Let's hear him tell us what he discovers:
And that's when I realize. In a sweet, cruel, beautiful moment of clarity, I smile, watch a crack in the cement, and speak to Audrey and the sleeping Doorman. I tell them what I'm telling you: I'm not the messenger at all. I'm the message. (5.the message.21)
Wait, what?
After running all over town, solving clues and helping strangers and friends alike, the point of it all finally becomes clear to Ed: he can—and should—care about his own life. He isn't a lost cause or a lazy good-for-nothing bum, and so long as he chooses to invest in being alive, he's got a meaningful and gratifying life ahead of him.