i'm sure a good number of predents actually use the site. quite a few of my current classmates are SDN alumni and back when i had interviews, being on SDN was like one of the big topics when i was talking with fellow applicants. only a fraction probably posts in the forums though, but i'm sure there are alot more people who don't post at all but gain advice from reading the forums. In fact, i would say SDN is probably the most useful resource when it came to applying for dental schools.