Elon Musk wanted to rebrand PayPal as X.com decades ago.Britta Pedersen/Getty Images Elon Musk rebranded Twitter as X over the weekend — a name that has long been one of his favorites. He had wanted to use the name X.com for PayPal over two decades ago. But focus groups thought the name sounded "seedy," according to Musk biographer Walter Isaacson. In X.com, Elon Musk sees the name of an enterprising business ready to change the world.