Ask HN: Online Dating ROI?

I just recently graduated from college, and my two partners and I have been working out of our apartment on our internet startup. When I graduated, I was single and I thought I would just bide my time, devote myself entirely to the company in the near term and hopefully meet someone down the line. I guess I underestimated how isolating it can be to work all day out of your apartment and I've been thinking about using online dating sites, but like many other entrepreneurs, I want to invest my time wisely.

I recently read in Super Crunchers, that eHarmony only creates marriages for approximately 1% of it's user base in a given year. Granted, I'm not necessarily interested in getting married just yet, but that statistic says to me that anyone who values their time shouldn't invest it in online dating (to speak nothing of the dollar cost of paid sites).

Does anyone on hacker news know the relative return on investment for other online dating services (Match.com, okaycupid.com, etc)? Ideally I'd like to get not just the rate of user marriages but also dating outcomes (where users end up dating someone they found online, say, for more than a month). And as a corollary, it might be interesting to know what dating methods work best. For instance, the most efficient investment of my time might be to join a local book club.