Realty Income (O 0.10%) and Agree Realty (ADC -0.87%) are two of the largest real estate investment trusts (REITs) focused on freestanding retail properties secured by net leases. Those leases require tenants to cover all operating expenses (including routine building maintenance, real estate taxes, and property insurance). That enables the REITs to collect very stable rental income, which allows them to pay monthly dividends. Given their similar strategies, most investors will likely only want to own one o ...