How can we get a handle on what Amazon’s mysterious Kindle statistic–a unit-based percentage of a percentage of titles, where books comprise an unspecified percentage of overall media sales–actually looks like? Given all the variables it’s very hard, but below is one potential formula, and you can adjust the assumptions as you wish. As reported above, North American sales for all media for the quarter were $1.245 billion. At the closest roughly comparable businesses, Barnes & Noble and Borders, book sales tend to comprise 70 to 60 percent of total sales. Let’s be conservative and start with 70 percent, which […]