For one thing, FaceTime is a multi-party tool which falls victim to the network effect. The first people to get an iPhone 4 had few people they could FaceTime with, so it wasn't very useful to them.
Siri, on the other hand, doesn't depend on anyone else having anything in particular. Siri would be just as useful if you were the only person on the planet able to use it. I think that will make a huge difference in adoption.
Siri, on the other hand, doesn't depend on anyone else having anything in particular. Siri would be just as useful if you were the only person on the planet able to use it. I think that will make a huge difference in adoption.