In reply to Jonas Paulsson.

I thought about timing the writing time automatically, by having a plugin actually time the amount of time spent in the Editor and optionally, how much time users spent creating comments. But that approach wouldn't work if the author didn't write a post inside WP and it wouldn't cover the time done researching.

I really don't get why sites use ETR though over a word count. For me, it makes me more time conscientious since time is scarce, it's only going to give me more reasons to bail. I don't really buy Cray's results either, much too small of a test to say anything conclusive for his site (let alone as a general practice).