While you read this blog.
This is a very rapidly declining curve. On an average visit, users read half the information only on those pages with 111 words or less.The powerful advantage of web publishing over print is the two-way exchange of information. How long you look at what, where you come from or go to, what you click - all these things give us immediate feedback on what's working or isn't.
In the full dataset, the average page view contained 593 words. So, on average, users will have time to read 28% of the words if they devote all of their time to reading. More realistically, users will read about 20% of the text on the average page. [More of an interesting study]
We're just not sure what some of this information means...