Not all the best things in life are free, as they say. But you can definitely try to give something out for sure. You can see this done all over the web. Free screensavers, free games, free download of programs. And what do they need from you? They just ask for an email address, your name and a little something more about you. Then you can place a check box on the registration form for sending of email. For sure, you can think of something to give out as well. If you promote online university then you have to get more informations.