Few people know more about online dating that Christian Rudder, co-founder and editorial director of OKCupid. Privy to the vast mountains of data created as millions of people answer questions about what they’re looking for in love, search through profiles of people in their area and flirtatiously message each other, Rudder has learned a lot from the numbers.

Rudder has given us insight into OKCupid’s dating algorithm in a TED-Ed lesson and visited our New York office to speak as part of our miniature TED session about love. To help you get in the Valentine’s Day spirit, here are some surprising facts we learned from Rudder about online dating behavior.

1. Women are more likely to get responses than guys. For a guy who writes a woman on OKCupid without any previous flirtation, he has a 25% chance of getting a reply from her. But for women who are cold-writing a guy — there’s a 40% chance she will get a reply.
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2. Women’s perception of men’s attractiveness may be more warped than men’s perception of women’s appearance. With the rise of pornography, plastic surgery and airbrushing, many people wonder — do guys know what real women look like anymore? The answer appears to be yes. When Rudder showed us a graph of the ratings men give to women on an attractiveness scale of 1 to 5 through OKCupid, there’s a normal distribution with fewer women falling at the 1 and 5 extremes and the grand majority getting ratings in the middle. However, when women rate men on a scale of 1 to 5 on attractiveness through the site, the graph skews sharply towards the lower end. Women overall rate many men as a 1, and shockingly few as a 4 or 5. Jokes Rudder, “A 3.8 for a guy is basically Hollywood material.”
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3. Still, men tend to email the most attractive women. While guys can clearly appreciate women in the center of the attractiveness spectrum,  that doesn’t mean they don’t aim for the top. Men of all levels of attractiveness tend to send the most emails to the few women rated across the board as a 5.
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4. Message length doesn’t appear to matter. Rudder was sure that longer messages would up a person’s chances of getting a response from the object of their affection. But it’s not true. Whether a message is the length of a tweet or the length of a novella doesn’t seem to matter in terms of chances for a reply. The numbers listed in item #1 hold tight — men have a 25% chance of getting a response and women have a 40% chance.
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5. If you don’t hear back quickly, you probably won’t. Rudder took a look at the length of time elapsed before a person replies to a message and how it corresponds to the likelihood that they will respond. In a fascinating twist, half of all replies are sent by the seven-hour mark. There’s a big drop-off from there in the chances of a reply. “Seven hours is the half-life of your hopes and dreams,” joked Rudder.
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6. Not all replies turn into dates. Getting a reply on OKCupid is half the battle — but it isn’t everything. There’s only about a 30% chance that a reply will turn into an actual conversation — a correspondence that lasts for three exchanges or longer.
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7. Despite the startling statistics, people do fall in love through the site. Every day, about 500 people disable their OKCupid profiles for a very specific reason: they met someone through the site that they’re embarking on a relationship with.

What have your online dating experiences been like? Which of these facts surprises you the most?

This post was written in February 2013 and updated for Valentine’s Day 2015.