The Ultimate Fighting Championship (r) is the world's largest mixed martial arts (MMA) organization, with over 625 million viewers and 142 million social media followers. The organization organizes around 40 live events each year at some of the world's most prominent stadiums, while broadcasting to over 900 million TV households in over 175 countries. The main event of every fight is contested under MMA rules; however, some events include other combat sports such as boxing and wrestling in their lineup. Of these events, approximately 12 million people attend an MMA event annually. UFC events are broadcast live to an audience of over 5 million people worldwide, making it the most watched MMA product in the world. In addition, more than 40 million people follow the organization on Facebook, Twitter, and Instagram. MMA is a global industry that spans across several countries with different legal systems, fighter eligibility requirements, and salaries. As such, it is difficult to accurately estimate the number of participants in the industry but it is known that the majority of fighters are male individuals between the ages of 18 and 35 from North America and Asia. In 2016, the organization had annual revenues of $400 million and operating income of $50 million. The bulk of its revenue comes from pay-per-view purchases within the United States while international sales account for another 20% of its total revenue. UFC events are considered some of the highest rated television programs in both the US and Canada.