1. as i mentioned before, you can't use EBITDA as an actual metric for a product. operating cash flow takes into account costs directly attributable to the product (COGS) and costs not attributable to the product (OPEX). we don't know how Amazon allocates their OPEX. at best, you can evaluate a product's profitability based on Gross Margin = Rev - COGS.
so for example, the iPhone sells for $700 and the COGS is $200. the Gross Margin on the iPhone is $500. Say OPEX is another $100.
Rev - COGS - OPEX = $600
now lets say air freight costs suddenly ballooned because oil prices spiked and increased OPEX 3x...
Rev - COGS - 3(OPEX) = $200
a. the iPhone is no longer a profitable phone because EBITDA is now $200
b. the iPhone still is profitable since the Gross Margin didn't change, but unexpected operational difficulties impacted the company (or business unit) and caused the decrease in EBITDA
which one are you going to choose?
if you are talking about a product stop using EBITDA.
2. why would Amazon be willing to take negative margins on the Fire? look at it this way. hardware is not their bread and butter. if the hardware giants Samsung, HP, and HTC are having troubles, it is reasonable to assume that as the new guy Amazon would probably get even lower margins than those three.
instead of farting around trying to gain operational efficiencies or negotiate for significant hardware volume discounts, why not create a tablet which will leverage Amazon's competitive advantages?
Apple runs iTunes at a break even or slight loss because there's no point for them to try and make money off $0.99. iTunes is just there to help drive hardware sales. Amazon will run the KF at a break even/slight loss because there's no point in competing with the existing players. KF will drive users to spend money on books, music, movies, and whatnot on Amazon... where the company make the majority of their sales.
3. you can not evaluate Microsoft based only on their consumer products just as you can not evaluate Apple only on their enterprise offerings. one is software focused and the other is hardware. a software focused company will have lower operating leverage thus easier to achieve operating profit, but each additional sale will not have much impact on EBITDA. a hardware focused company will have higher operating leverage thus harder to achieve operating profit, but each additional sale will have significant positive impact on EBITDA. asking Microsoft to bring in $13B is like asking Apple to lower their fixed costs to Microsoft's level. not going to happen... their cost structures are different.
4. you're really off the mark with a lot of your questions and statements. i don't know if you're in high school, college, working or what... but go enroll in some business/finance/strategy classes and learn the basics of analyzing companies. seems like you're at least interested enough to mention EBITA... that's a lot better than the usual margins/market share/stock price arguments i see around here.
According to Amazon support forums Kindle Fire return rates are anywhere from 25-50% and remember Amazon makes ZERO EBITA on each and every single unit. It's a pathetic business model. Apple kills the entire tech industry.