Leading net-lease retail real estate investment trust Realty Income (NYSE: O) is trading just above its 52-week low, and part of the reason for this is the weakness in the retail sector. However, most of the perceived weakness in the retail industry doesn't apply to Realty Income, and I see a long-term buying opportunity taking shape. Here's why Realty Income isn't like other retail investments and the long-term potential of the company's business model. 1. This chart shows why Realty Income is a different kind of retail investment There's a fear among investors about anything involving the brick-and-mortar retail business, but don't be so quick to group all retailers into the same category. Sure, department stores and apparel retailers are struggling, but some areas of retail are doing just fine, including the three main property types Realty Income invests in. The vast majority of Realty Income's retail tenants operate in one or more of three categories: Non-discretionary retail, that is, businesses that sell things people need. These tend to suffer less during recessions, and are often resistant to e-commerce competition. Service-oriented retail, which is virtually immune to e-commerce competition. Think fitness centers and restaurants. Low-price retail, such as dollar stores. These are e-commerce resistant, and many actually do better in recessions as people seek bargains. Image source: Realty Income investor presentation. 2. The net-lease structure helps keep occupancy consistently high Realty Income is a net-lease REIT, which is a specific type of lease structure that minimizes tenant turnover and creates a steady income stream. Specifically, a net lease requires the tenant to cover variable costs of property ownership, such as real estate taxes, building insurance, and some maintenance expenses. These leases are long term, with initial terms often 15 years or more, and they typically have annual rent increases, or "escalators," built right in. The result of this net lease structure, as well as the recession and e-commerce-resistant tenant base, is that occupancy stays rather high. In fact, more than 98% of Realty Income's portfolio is currently occupied, and this figure has never fallen below 96%, even during the Great Recession. Image source: Realty Income investor presentation. 3. Shareholders have been rewarded with steadily growing income Consistent occupancy and growing rental revenue has allowed Realty Income to give its shareholders steady raises over the years. The company, which pays dividends monthly, has increased its payout 91 times since its 1994 NYSE listing, at an average annualized growth rate of 4.7%. Perhaps more importantly, the payout has never been cut. In fact, Realty Income is a member of the S&P High Yield Dividend Aristocrats index for its rock-solid dividend growth history. Image source: Realty Income investor presentation. 4. Realty Income is a total return investment REITs like Realty Income are total return investments, meaning that they earn money from rental income that is then paid out as dividends, and they also grow in value over time as the underlying properties appreciate. Image source: Getty Images. This combination can produce some pretty amazing long-term results, as any investor who bought into Realty Income's 1994 NYSE IPO could tell you. In fact, the stock has generated a 16.9% annualized total return since that time, or a total return of 3,120% altogether. To put this into perspective, consider that a $10,000 investment at the time of the NYSE listing would be worth more than $320,000 today. O Total Return Price data by YCharts. 5. But you must reinvest your dividends to achieve results like these As a REIT investor, there's one key point that's crucial to be aware of. The excellent total return capability of these investments is dependent on dividend reinvestment. Every REIT you own, including Realty Income, should be enrolled in a dividend reinvestment plan (preferably in a tax-advantaged account like an IRA). That way, as soon as you're paid a dividend, it is used to purchase more shares of stock, which then generate even more income. To illustrate this, let's say that you invested $10,000 in Realty Income's 1994 NYSE listing, but chose not to reinvest your dividends. Your shares would have grown in value to about $72,000, and you would have collected roughly $42,000 in dividends over the past 23 years, for a total value of $114,000 -- 64% less than if you had reinvested your dividends. O data by YCharts. 10 stocks we like better than Realty IncomeWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the 10 best stocks for investors to buy right now... and Realty Income wasn't one of them! That's right -- they think these 10 stocks are even better buys. Click here to learn about these picks! *Stock Advisor returns as of June 5, 2017Matthew Frankel owns shares of Realty Income. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.