Opening Line of a Novel - Important or Just Crucial? You Decide!

Dale James Arceneaux has a lively post on how to stage a good opening for a novel. I disagree with him slightly, in that I believe that the opening for Demon: A Memoir is actually perfect, not just okay.*

As for me, I'm a hundred pager. If I make it to page 100 and am not yet engaged in story, I'll put it down for good. I also realize that I am not the droid that Penguin is looking for.

*The line is this: "It was raining the night he found me." It works because ostensibly, we are reading a memoir. In eight words, Tosca tells us that this is a biography of a man who is sought under unfriendly conditions, that the story is about a relationship between two people who are not intimate with each other, but needful, and that our hero is hiding from something. If you can say that compellingly in less space, I'd love to see it. The paragraph that it introduced is haunting and tense.

In short, the devil had me at "Hello."