It didn’t get worse, and that was more than enough.

Amazon ’s revenue growth has been decelerating for two quarters and margins had been ticking downward, on and off, for longer than that. But in the first quarter, reported yesterday, sales grew by the same rate as in the fourth quarter, gross margins stepped up nicely and operating margins held at about 1.5 per cent – razor thin, but positive. The stock leapt as much as 15 per cent in after-hours trading.

Amazon’s balance sheet and cash flow statement were a bit less encouraging. Trailing 12-month free cash flow was the lowest in at least three years. Cash return on invested capital was 12 percentage points lower than a year ago. Amazon is still pressing the investment pedal as hard as it can and the toll on returns is escalating.