one of the first billionaires david rockefeller used this secret to build the biggest network of all time rockefeller's massive rolodex held over a hundred thousand individual contacts that he used to grow one of the largest generational fortunes the world's ever seen and after his death at the age of one hundred one years old the wall street journal was able to sneak a peek at the greatest contact list of all time and what they found was shocking rockefeller didn't just keep contact information on his associates instead he used a human psychology hack to make people believe he was an incredibly caring man knowing that people love to talk about themselves rockefeller would take notes on any meaningful detail from every interaction he had with people things like the names of their children the families health or the achievements they were most proud of than anytime he'd meet these people again he'd review his notes and use the information to build meaningful relationships that lead to lucrative business deals when he would say things like the last time we spoke your daughter had gotten a soccer scholarship to brown how is she doing there people's faces would light up and they would let their guards down and think of rockefeller as a friend instead of just a business contact rockefeller said these relationships were never transactional but transformational an average business people conduct transactions but great leaders make transformations