SMH.COM.AU - Feb 14 - OkCupid's pitch says: "We use math to get you dates." Co-founder Christian Rudder is crunching data from millions of users to come up with insights such as women are most attracted to men their own age, and men are most attracted to women aged 20-22. "What people say they want, and what they really want, are very different in practice," says Kari Taylor, from RSVP. RSVP switched from profile-based matching to behaviour-based matching a few years back and saw an 80% surge in users saying yes to conversation requests. eHarmony's predictive model for attraction has improved up to 400% in the past couple of years. An algorithm for attraction is possible given how much data is available. But the real question is whether that's the direction the industry is heading. The biggest thing in the online dating is Tinder, an app that doesn't use any info except a photo.