On engagement, we're already seeing that mobile users are more likely to be daily active users than desktop users. They're more likely to use Facebook six or seven days of the week. ↗
Think of the earth as a living organism that is being attacked by billions of bacteria whose numbers double every forty years. Either the host dies, or the virus dies, or both die. ↗
People love the electric rake. You just hit it or whatever you want to do. You can't play 'Swanee River' on it. You have to just make terrible noise. Occasionally, it will make a sound like a note. ↗