The Wall Street Journal's Digits blog takes a look at "crap apps" -- those pieces of junk on the App Store that do one thing and do it pointlessly, whether that thing be farting or belching or making the sound of fingernails on a chalkboard (yes, really) or what have you. And they come up with a very intriguing, albeit obvious, reason that the App Store seems so filled with completely terrible and silly apps. Why? Because they sell.
Movies, TV shows, cars, food, people. There's crap in the world because we actually like crap. Done. No fancy Wall Street Journal analysis needed.