Slate with a nice article on NNT – a statistic that is not advertised in many pharmaceutical studies:

In June, the New York Times ran an article headlined, “Breast-Feed or Else.” It suggested that experts believe that “breast-fed babies are at lower risk for sudden infant death syndrome and serious chronic diseases later in life, including asthma, diabetes, leukemia and some forms of lymphoma.” Yet, the article never mentions the NNT for breast-feeding to prevent these scary diseases. Neither does any general-interest press article in LexisNexis, a database. There’s a reason for this omission: The NNTs are astronomically high. Reasonable women might think that breast-feeding isn’t worth the trouble—a conclusion that you don’t want drawn if you’re promoting breast-feeding at any cost.