Just sell something people never stop buying.

The best business to start is one where people don't stop paying and the easiest way to figure out what things that people buy that they don't stop paying is to look at your own credit card bill, your own bank statement, and look at everything that you pay for every month. The reason real estate fundamentally is such a big industry is that people don't cancel their rent. You have to keep paying your rent. People don't cancel their internet bill. People don't cancel their alarm system. People don't cancel their insurance. And so those are why those industries, if you look big picture, why those industries are so big and so long lasting. They predate the tax code, some of them, they survive wars, and they're 100 plus year institutions. And guess what? You don't have 100 plus year institution by not making money.