A recent MarketWatch video explores what it takes to make a living off Twitter. If you're a celebrity, you're already halfway there, as the key to any successful strategy is a built-in following. 

Take Kim Kardashian: She has about 17.5 million followers, while her TV show only has 3.5 million. To marketers, says reporter Quentin Fottrell, "the more followers you have, and the more interactive you are with the marketing companies that broker these deals for you, the more money you're going to get." 

But just how much money are we talking about, exactly? A Kardashian retweet yields $100,000, while the online fundraiser Twitchange drew $540,000 during a charity auction for Haiti. 

Watch the video below to see what other tweets sound like ka-ching: