“synergistic byproduct spun-off”
If you think that using “manager-speak” instead of plain English adds weight to what you saying and makes you look clever, you are wrong :)
As for the actual topic. What is Amazon’s core business? If you talking about retail, then it does not give much advantage in terms of cloud storage, but if you talking about AWS, then yes, it makes the difference (whether it is core or not — it is debatable).
In terms of storage and compute AWS is much larger then the compute required for Amazon retail, effectively making Amazon’s retail a beneficiary of AWS and not the other way around. It is just another business where Amazon branched to and which became more successful then all its competitors.
Apple uses both AWS and Microsoft’s Azure to store the data and they are not in the cloud platform business.
