Users love to have the pre-written 'http://' in the form. So go to your form, and add:
You can promote it through a lot of ways, featured listings, email blasts and so on.. it's just not the best time to start promoting a proxy as school is overCode:value="http://"
ProxiesLounge made a good post to advertise your proxy for free:
10 Free Methods To Promote Proxy Sites & Proxy Lists | Proxies Lounge