Iron Mountain provides physical document storage and increasingly data center and digital information management services, having built its original business around storing paper records and archives for businesses that need to retain documents for legal or operational reasons. As a real estate investment trust, the company distributes most of its taxable income to shareholders as dividends, with its physical storage business generating fairly predictable, recurring revenue from ongoing storage fees on records that customers rarely retrieve. Iron Mountain has expanded into data center operations in recent years, applying its expertise in secure facility management to the growing data center real estate market alongside its traditional paper storage business. The company's physical storage business benefits from high customer retention, since moving large volumes of stored records to a competitor is costly and operationally disruptive, giving Iron Mountain unusually sticky long-term customer relationships.