The market is huge and generates more films and more profit than Hollywood. From DVDs to print media, online tube sites to sex toys and merchandising, the adult entertainment industry is thriving. In this feature we take a look at the top ten porn companies that contribute the most to the porn market both in terms of money and reputation. Despite the fact that the material they produce is widely available, well marketed and easy to find, most of the porn companies are not that easy to understand when it comes to their ownership and structure. Many of the adult entertainment companies behind the powerhouses of internet porn are owned by holding companies, linked to defunct businesses and are listed with offshore headquarters. No doubt much of this is linked to the legality of their operations with porn being legislated with varying degrees of censorship across the world. It would be hard not to be cynical about the financial benefits that may come with these complex structures and some may certainly be established in this way to avoid heavy taxation.