You might have something there.
Phone sex is obviously still a profitable business so there "could" be a successful mariage of such with internet. Don't necesarily need the phone though, most cams have a mic in them and a lot of computer owners have microphones, if not, still offer the customer the ability to phone of course.
Try developing something small to see how users like it. If it becomes popular, seek investment. Oh but patent the idea first of course so if it skyrockets, you don't have competition
