While watching Rand talk about this I was looking for the option to instantly buy him a beverage of his choice. To often I see these reports on best practice and averages that aspire to address every type of content in every industry. Not all audiences are the same for all industries. I was thinking about this and a great comparison could be measurement conversion in cooking where a short concise answer that is less than 10 words is more useful for the audience versus content describing the history of cooking flour where we would expect longer content and even citations to more content both online and off.
Write a lot of content to become a better content creator. Publish content for the domain or site that your audience would find useful. Review your metrics always.