Amazon is a retailer and cloud computing provider and a video streaming service and a TV producer and a device manufacturer and a grocery store and a bank for small business loans and a hundred other things... At what point does the umbrella brand start to confuse people?
Bezos must have a brain the size of Texas to keep all these moving parts in mind.
For example consider Sony: Sony Computer Entertainment (gaming), Sony Mobile (phones), Sony Pictures (movies), Sony Music (music), Sony Life (insurance), Sony Bank (banking), Sony Corporation (electronics), Sony Visual (imaging), Sony Medical (medtech)
Fun fact: Twitter is worth more than Sony. Billions more.
And Sony as a brand is split in different groups depending on the activities (e.g. finance, music production, content licensing, network provider and who know what else). Twitter's not in the same league.
My mom would affiliate Samsung with TVs. I'd probably put them with computer monitors and phones.
They also build skyscrapers and power plants (Samsung C&T Corporation), and ships (Samsung Heavy Industries). They also sell Life Insurance in South Korea.
(Really, that's two separate companies which license the brand from http://en.wikipedia.org/wiki/Westinghouse_Licensing_Corporat...)
I'll say however, that Samsung appears vastly undervalued. GE is trading at about 20 times earnings, Samsung is trading at 20 times just its last quarter alone (and around 5 or 6 times trailing four quarters).
Also worth noting, that despite being more profitable than Apple, Samsung trades at a 60% discount to AAPL.
Vis-à-vis Amazon, I'm not sure it's a problem yet, I think of them as a retailer, AWS and Kindle, etc as separate brands. I don't see the problem at this juncture.
The first thing in my mind is almost always one of their technical services, most specifically AWS
My assumption on Bezos is that half is he's an obsessive genius, and half is he hires very well. You need the right people to keep the parts moving without detailed guidance.
You can tell that Google is aware of this challenge by the simplicity of their Search screen. They keep a lot of their offerings hived away from the top screen.
The danger of a conglomerate is that a culture or decision-making paradigm suitable for the dominant business(es) might not be good for others. E.g., smaller businesses might get ignored because they don't matter enough. Or they might not be allowed to move quickly and take risks. E.g., Xerox found that selling LISP machines and copier paper mixed badly, as reorders of the latter were held hostage to the immaturity of the former.
On a serious side, it stops when Bezos can't make it work and there aren't many things that fit in that category. I'll see you at Amazon U.