Yeah, it took me a while to get it too. Basically if 100% of the people who view your story actually reads some portion of it (what portion that amounts to is the $50 question), then you end up with a 100% ratio for that story. But if the story was 2 minutes long, and the average time each reader spent was less than the entire length of the story, then they clearly have not read 100% of the writing. Hmm. Hope that didn’t make the confusion worse :-)