Personally I think a FB ad or pitching to friends is a little too impersonal and not a high enough likelihood of many crushes between that group. Instead I'd aim for a small but well interconnected network first, like a single dorm building. The next week, the next one over. Eventually, it could own the campus' attention for a bit, then maybe the next school nearby. Getting a single dorm on board could be as simple as setting up a table in the lobby with a couple laptops and giving out donuts to people who sign up.