Commandment #6 is, sort of, the next step in that process of making clear to the audience how your It solves the problem.
One way to describe It quickly and cogently, I find, is to analogize to, or contrast your It with, the other, existing Its out there. Sometimes (most likely, the contrast situation), the other It is a product or service that youre going to kill off, replace, compete with, complement, or relate to in some direct way because your It and the other Its are solving problems in the same or similar markets.
Sometimes, however, its useful to analogize your It to an It from an unrelated market. This works best when the other It is a popular social artifact such as Blog, Google, TiVo, Podcast, etc. (good way to tell this is when the social artifact formerly just a noun, has morphed into a verb due to its popularity).