137. Top Level Domains (TLDs) – long gone are the days when your only domain ending options were .com, .net, and .org.
Over 1000 privately owned TLDs are now available from .xyz to .ninja.
You can make money (and have a recurring income stream) by starting or buying your own TLD and selling the individual domain names in 1 year registration increments. The goal is to not only sell the domains, but to have the domain name owners continue to renew year-after-year.