Besides photographs, each user's profile could include any number of personal details including age, height, weight, education, marital status, number of children, and smoking and drinking habits.The data set includes some 1.1 million interactions between users.
Those 30 million people have generated billions of pieces of data.
And because most dating sites ask users to give consent for their data to be used for research purposes, this online courting has played out like an enormous social science experiment, recording people's moment-by-moment interactions and judgments.
Perhaps unsurprisingly, men in their 40s tend to be more interested in younger women. "Women care quite a bit more about the height of their partners than vice-versa," Bruch says.
In pairings where men were about 17 centimeters (or about 6 inches) taller than the woman, the woman was about 10 times more likely to browse the guy’s profile, whereas the man was about three times more likely to browse hers.
The twisted murderer, who was just 10 when he tortured and killed James Bulger, was recalled to prison last week after police discovering sick child porn images on his computer in a routine check.
But the Daily Star Sunday has since reported that the sicko had been trying to chat to single mums on a "well-known, well-used dating site".
A team led by Elizabeth Bruch, a sociologist at the University of Michigan, Ann Arbor, tapped into this torrent of dating data.
Because of a nondisclosure agreement, the researchers can't reveal the exact source of their subjects, describing it only as an "established, marriage-oriented, subscription-based dating site" from which they randomly selected 1855 people, all based in New York City.
When it comes to the early stage of dating, it seems to be all about the deal breakers.