So, though we can’t be sure, it looks like the capex is not going up because Amazon’s existing business has become more expensive to run, but because Amazon is investing the growing pool of operation cash flow into the future. All of this brings us back to the beginning - Amazon’s business is delivering very rapid revenue growth but not accumulating any surplus cash or profits, because every penny of cash is being ploughed back into expanding the business further. But, this is not because any given business runs permanently at a loss - it is because the profits from what is already there are spent on making new businesses. In the past, that was mostly in operations, but in recent years the investment firehose has again been pointed at capex.
How long will this investment go on for? Well, do we believe that the conversion of products and businesses to online commerce is finished? Let’s rebase that revenue chart, and look at it as share of US retail revenue. Excluding gasoline, food and things like timber and plants,all hard to ship, at least for now, Amazon has about 1%.