[fjabre]

Design can be a powerful weapon if done right - just look at Apple..

However, it's very difficult to achieve Apple's near perfect blend of aesthetics & function so I think most people give up and build anyway, making something perfectly functional i.e. Facebook or Gmail, but not awe-inspiring.

[tptacek]

Apple's design is also more data-driven than it appears --- although it's clearly not as coldly rational as Google's.

[boucher]

Data driven from an individual collection and observation perspective, perhaps. Apple doesn't AB test its products.