
Every 100ms of latency costs Amazon 1% of profit - nreece
http://radar.oreilly.com/2008/08/radar-theme-web-ops.html
======
spon
Every unsupported claim you read makes you 1% dumber.

~~~
toffer
Greg Linden used to work at Amazon. From an older blog post of his:

"In A/B tests, we tried delaying the page in increments of 100 milliseconds
and found that even very small delays would result in substantial and costly
drops in revenue."

[http://glinden.blogspot.com/2006/11/marissa-mayer-at-
web-20....](http://glinden.blogspot.com/2006/11/marissa-mayer-at-web-20.html)

~~~
sysop073
Have they tried speeding it up 100ms to see if they gain revenue? I can't
believe such a minuscule change has such a huge effect, that's astounding

~~~
zenspider
Disclosure: I used to work at amazon.

I find it immaterial considering the easier thing to speed up is the number of
HTTP requests on the site, and that has clearly gotten worse over the years,
not better. I pushed heavily to get HTML cleaned up and valid (showing an easy
10-20% reduction with HTML alone), reduce the amount of javascript, etc. It
simply wasn't a priority. To be fair, at the time I was there the priority was
to grow as fast as possible and deal with profits later.

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sh1mmer
It's kind of ironic then how slow Radar is.

Seriously though, site responsiveness is important. If you haven't seen it
YSlow is pretty awesome (<http://developer.yahoo.com/performance/>).

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gojomo
The source slide actually says "+100 ms -1% sales". A 1% drop in sales would
likely cost even more in profits, given fixed costs.

In either formulation, it's within the range of plausibility.

In my experience, a single change that makes a web server faster causes a
slow, steady increase in traffic over the next few days/weeks, as the audience
reacts to the new responsiveness.

Note also that Google considers page load latency in scoring ad relevance, and
almost certainly natural search result ranking as well. So everything improves
with speed.

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

~~~
jgrahamc
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.

~~~
time_management
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%.

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babul
Empirical evidence?

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blogimus
"The techniques of web ops are being hoarded by some companies"

Are these techniques patented? Otherwise how does one "hoard" a technique?

~~~
shard
Perhaps through the use of trade secrets.

