The market's primary focus for cloud vendors isn't just on revenue growth, but also on the cost of that growth. I created a metric, shown in the chart below: subtracting the same period last year's revenue from the current quarter's revenue (i.e., the year-over-year increase in revenue), and then dividing that by capital expenditures, roughly shows how much new revenue each dollar of capital expenditure generates. (I also did a quarter-over-quarter comparison, but the year-over-year figure is more meaningful.) As you can see, Google and Microsoft have significantly improved efficiency; Google's main decline was dragged down by its core advertising business. Other vendors like Amazon and Oracle, however, are clearly experiencing a decrease in efficiency.