The Web was a huge driver of Unix adoption. Before the Web came along, Unix was on the ropes. The conventional wisdom was that Windows NT would eventually finish it off, owning the server space the way regular Windows owned the desktop. But all the early tools for standing up a Web site were Unix-centric, simply because the Web's roots were in science and academia rather than traditional corporate computing. So when the Web started getting big, Unix started getting big too, and never really stopped.
Presumably someone at SCO thought an online pizza ordering service would be a good way to demonstrate the value a Web site could have for businesses. And that demand for Web sites would in turn mean demand for SCO's Unix products.