I think quizzes/etc. on LJ got them early users, but then there was a big decline in LJ around the time MySpace got popular (2005-2006?), which probably hurt OKC. FB becoming popular essentially killed it. The blog, IIRC, was around that time -- so for a while the "dating" site had a bunch of accounts of people who were originally there for quizzes, many of whom were no longer active.