I just tried out Ben the Bodyguard [1], and honestly, though I see what they're going for, the interaction is not great. For one, as I scroll into the animation, there's a big spike in CPU and the browser freezes for a second. Then, I have to do my best to scroll at just the right speed in order for the animation to look smooth, and to be able to read the text. I guess this is kind of cool, and maybe many people enjoy it, but for me, it's an awful lot of work you're asking me to do to find out about your product. (Your as-in “one”.)
Yeah, this highlights another point—the animations (and the effort required to view them) can be so distracting that this may not even be an effective way to educate me about the product.
[1]: http://benthebodyguard.com/index.php