Amazon

[Grieve]

I call it the Apple "tar pit" effect. Someone buys a Mac, loves it, and goes looking for accessories or add-ons for it and discovers that much of the wide world of manufacturing and invention is sealed off from them. If they see anything they want and Apple doesn't make it (or doesn't make a reasonably priced version of it) then they'll have to dump Apple entirely in order to use it. e.g., your selection of hardware upgrades (like video cards) is very limited and your ability to use 3rd party accessories (programmable mice, keyboards, headsets) can depend on if the manufacturer made a driver for Mac or not.

You are talking about geek stuff. How many people buying a family computer need a programmable mouse? If you are arguing that Apple targets the mainstream rather than gamers and techogeeks, I'd agree. But they are missing out on a pretty niche market.

Digital content providers?

What do you mean - produce their own digital content, like movies and TV and music and so on? They may end up doing that, but I think that's a pretty risky business in and of itself. Isn't it better to let others make the content while they continue to sell it with a 30% take, as now?

Enterprise servers?

http://www.apple.com/server/

Enterprise software?

Again, why not let others write it while they take their 30% cut for the mac app store?

Amazon continues to branch out in sensible ways. Apple keeps things close and their vision for the future seems to be "my way or the highway". There's a risk that it'll be the highway.

Amazon continues to generate lower profits - the most recent quarter was 35% down from last year.

And I'm not sure exactly how Amazon have branched out from their core business. Everything they do (e.g. Kindle, Kindle Fire, cloud) is aimed at making people buy more of their stuff...just like Apple.