See, writing a dummies book is like starting a farm. First you have to get some land, seeds, fertilizer, and a barn. Than you need to find a few people to work on it with you. After a year of work, you'll have fresh produce you can sell. Once your vegetables, grains, squash, and fruit get to the grocery store, it doesn't matter how much fertilizer or water you gave them, it's just tossed into a bin with all of the other products of the same category. As long as it has that little plaque in front of it with the name of the item, people will but it.
Personally, I find dummies books to just be filled with these idiotic "real-world" comparisons. I prefer more serious books without the little one panel gag comics and categorized notes, but I know people who do like them. But that's what libraries are for.