[yazaddaruvala]

Disclaimer: I work at Amazon and own AMZN, but I have no inside knowledge about this and my opinion is my own.

If investments into efficiency and scale can produce AWS, and create an entirely new market segment; couldn't continued investments into efficiency and scale produce the next-AWS?

[dx034]

It could, and finding the next big thing is extremely profitable. But few companies are able to repeat that process. However, with enough money AMZN could become like Microsoft and successfully build their own products if others have shown that it's worth it. Microsoft also uses profits from some business lines to pay for losses in a lot of ventures of which only very few work out.