Sales growth in Amazon’s fourth quarter, reported on Tuesday evening, was 22 per cent, the slowest rate since 2009. The figure a year ago was 35 per cent. Sales growth fell hard when measured in absolute dollars, not just percentages. Operating margins were below 2 per cent, 40 basis points better than a year before, but well below levels seen in earlier years. Free cash flow was down 15 per cent on the year, even after the $1.4-billion (U.S.) Amazon dropped on new offices is excluded, on the grounds that it is non-recurring. The company’s outlook for first-quarter revenue was below expectations and suggests further deceleration.