Good marketing may get people in the door the first time, but good product design gets them in the door the second (and third, and fourth, and fifth) time.
Apple isn’t dominating because of clever marketing. They’re dominating because they make awesome products that people can’t wait to use. And when they roll out a new version, existing customers will wait in long lines again to upgrade, without thinking about it, because they know it will be great. They can buy sight-unseen because they trust Apple to deliver what only Apple can deliver, the perfect harmony between hardware and software.
And they know they’ll be able to simply turn it on and start using it.