John, who runs the personal-finance blog ESI Money, has spent the past few years interviewing millionaires. He found that many employ a simple three-step strategy to build wealth: Earn good money, save it, and invest it. Contrary to popular belief, it doesn't take a lucky big risk or an inheritance to become a millionaire. Sometimes, simplicity is key. That's particularly the case when it comes to building wealth, according to John, who runs personal-finance blog ESI Money and retired early at the age of 52 with a $3 million net worth.