Don't be scared away by the retail-oriented nature of Realty Income's portfolio. : Realty Income (NYSE: O) is a real estate investment trust, or REIT, that focuses on free-standing, single-tenant retail real estate. The company is a large REIT with roughly 5,500 properties in its portfolio rented to 257 different commercial tenants. It's also worth pointing out that Realty Income is not a pure-play retail REIT. In fact, about 20% of the portfolio consists of nonretail property types, particularly office and industrial properties. This adds an element of diversification, and also gives Realty Income additional opportunities to find value-adding acquisitions.