Hacker News Reader

If I've decided to purchase something from Amazon.com, I doubt an eye-blink's worth of waiting will change my mind.

You are probably correct, but if you haven't decided then it probably does.

Just to be pedantic an eye blink takes 300 to 400 ms. Amazon's claim is that delays 3 to 4 times less than an eye blink are annoying to people.

Mean reaction time for a human is around 200 ms for a visual stimulus so Amazon is talking about faster than normal reaction time as well.

Frame rate in video games is between 30 and 60 frames per second or one frame every 16 to 33 ms. Cinema is 24 fps or one frame every 40 ms.

So it would appear that Amazon is saying that a delay that a human can perceive is troubling and results in lost sales.

I doubt the dropoff curve is linear. It's probably negligible up to a small threshold (500 ms?) with exponential decay in the tail. I'm willing to believe that a 1-second delay is a 10% hit, though I wonder how that would be measured, but this doesn't necessarily entail that 100ms costs 1%.

Reply on news.ycombinator.com