Interesting read about Game Development

So I'm building this GDD so I don't go too far off-the-grid in this "Made for the Rift" game that I'm "attempting" to create, and came across an interesting read dealing with the identification of the target audience.

http://www.cms.livjm.ac.uk/library/Archive/GDTW2004-Publications/ChrisBateman-Designing%20for%20Different%20Play%20Styles.v1.3.pdf