They pretty much own the Audiobook market with Audible all of the publishers licence them their collections, Kindle is the largest E-book market along with the E-reader market. The kindle fire is pretty much the market leader in sub $100 the bargain bin tablet segment last I checked.

>>But have they really had much success elsewhere?

The word 'e-commerce' might look as one word here, but if you see what it takes to make it run, there are several big constituent parts of it, each of which could be a big business in its own right.

I imagine at some point, Amazon could likely offer shipping-as-a-service like Fedex or UPS. Or its supply chain or warehouse management expertise.

In fact aws was born when they realized they could rent out servers and infrastructure service they were using in Amazon.

Not much other success of global consequence, no. It's a myth that Amazon is gobbling up the world. People just like to throw around dramatic statements about big expansive corporations. It plays well to people's fears. You see it in all instances, without exception. Microsoft previously swallowed the world up and took over all businesses (as declared by numerous magazine covers in the 1990s). The dramatic performances put on about how Microsoft was going to own everything, is farcical in hindsight (and it was a joke then too). The exact same thing will hold true about Amazon. They won't own everything and the world will in fact keep on spinning, they're just the latest Big Corp in a very long line of them. Their run will fade just the same, too (20 years ago Walmart was going to own everything in retail and they were supposedly unstoppable, the headlines of dread were non-stop; Sears before that).

They have plenty of competition in cloud (they are in fact persistently losing market share). Their realm of dominance so far is ebooks and online traditional retail. There is nothing else that they truly dominate.

Amazon has overwhelmly failed at their ventures. They fail frequently and it gets entirely ignored by the doomsayers. They don't just take over industries, they flop at it routinely.

They also bought twitch, which I'm sure they have some business ideas to increase twitch's userbase past gamers and to target mainstream audiences.