U.S. investment icon Warren Buffett introduced himself in his first posting on social media Web site Twitter by saying he had arrived. \"Warren is in the house,\" Buffett wrote Friday morning, as he entered an online discussion about women in the workplace. The conversation also included Fortune senior editor-at-large Pattie Sellers. \"This is the first social interview that Warren has ever done,\" Sellers told CNNMoney. The Twitter discussion was a follow up to Buffett\'s article on women in leadership roles that was published by Fortune Thursday. \"Fellow males, get on board. The closer that America comes to fully employing the talents of all its citizens, the greater its output of goods and services will be,\" wrote Buffett, the chief executive officer of investment firm Berkshire Hathaway. Buffett named Fortune\'s finance journalist Carol Loomis, former Washington Post executive Katharine Graham and his first wife, Susan Buffett, as three women he admired. He said his definition of success was \"being loved by people you love.\" He also said any country \"that is only using half of its talent has a great future using 100 percent of its talent.\" \"Just think about what you can do when you get the whole team out there,\" he said.