That line is always one of my favorite lines. It is also now synonymous with a big budget Hollywood franchise and one that does some amazing marketing online!
I'm not going to get into the nitty gritty on how the viral program worked, but you can find that information all online on sites like Wired Blogs. I want to point out something more basic than that. I want to point out that good marketing sells a good product but good marketing cannot sell a bad product.
You've heard the old saying, "that's just putting lipstick on a pig". Well, that's what we see with too many Hollywood campaigns (remember Snakes On A Plane?). You can dress it up but if it's still a bad movie, then no-one will go see it (at least aftre the first weekend)! My point is that I've always stressed that the Promise of the Brand needs to match the Experience of the Brand and with the Batman campaign online, that is 100% effectively done. The online marketing teased the brand, and it fed the fever that the fans had for the product and the product delivered. It's the same with Apple and many other brands.
Brands forget that they need to be sure the product is as strong as they promise. Don't put out a less than favorable product. Go back to the drawing board of you have to. It will be worth it in the end.
And if you're Warner Bros., get to work on Batman 3. Please!!!