[fjtorres]

Amazon didn't leverage its bookstore to build Kindle.
That would've been illegal. And has been repeatedly investigated.

Kindles don't *have* to get their books from Amazon nor do Kindle ebook buyers have to buy Kindle readers. The famous lockdown, isn't.

Consumers buy Kindles because the features and the price satisfy.
For years, Kindles were the only readers that didn't need a PC or online access. For a year, they were the only source of Pearl screens you could *buy*. They always get the new eink screen tech first. Look at the Voyage, is there still anything really like it out there? No.

Amazon has been very careful *not* to break any competition laws and tying is illegal.
Walled gardens are not but even there Amazon has been careful to leave enough of a gap to avoid legal challenges.

The primary reason for Amazon's dominance is the same it's always been: they do a good enough job at everything and the opposition doesn't. They have been gifted with singularly inept enemies who help them every time they try to hurt them.