Epub has longevity and global reach.

Comparing cost and global reach, the scale of the circle for web, iTunes, and print is proportionate to the cost expenditure. The cost expenditure for each medium is relatively close at $240, $326 and $179. iTunes provided stats on number of views and location of the epub. Locations in Figure 8 are colored by continent with length of the line scaled to the distance reached with origination being Madison, Wisconsin. The number of readers is represented by the same number of lines.

The web and print versions have been active for one year with activity at a halt. The iTunes version has been active for six months. It is projected that the iTunes version will far exceed web and print over its lifetime in continents reached and number of views. iTunes traffic is not driven by a limited audience, but rather random access from a worldwide audience of 51 iTunes stores in as many countries, so it is expected to continue to grow.