Nope, it was a totally new site, new userbase. We learned while building SparkMatch that we wanted to do dating. But when we started OkCupid, we had all left the TheSpark/SparkNotes a bunch earlier, and there was nothing from SparkMatch on OkCupid. The only connection was a paid advertisement. We actually paid TheSpark to post an announcement of our new site, which got a bunch of the old SparkMatch users to try it. But, interestingly, it was LiveJournal (memories!) that drove most of our early growth, not TheSpark.

Also worth noting: OkCupid launched day 1 with the dating system as it is now -- answer arbitrarily many questions in 3 parts to build your own custom matching "algorithm". But we made it easier at the beginning for users to introduce their own questions.