So, you've flirted in the chatterbox, and you've msg'd every single one of the ninjagirls with increasingly creepy propositions, but none of them were impressed, and you're still single. It's time to consider the world of internet dating websites.
OKCupid is one such website.
The basics
First off, for those not in the know, what are the basic things that OKCupid shares with most other dating websites?
Profile
Every user has a "profile". Firstly, the profile contains basic information about the user: their gender, the gender(s) they're interested in dating, their height, etc. It is also the space where the user can write their own personal spiels, filling in such daunting sections as "My Self-Summary" and "What I'm Doing With My Life".
This section is like the user's dating CV, where they try to sell themselves as being a wonderful human being worthy of hugs and kisses. The site also encourages users to upload pictures of themselves, which appear on the profile too.
Messages
Obviously you need some way to contact the other users. Rather than require you to give your real contact details to people who are potentially creepy internet stalkers, OKCupid (like other dating sites) has its own internal mail system, enabling you to chat to the other users inside the safe OKC sandbox.
As well as messages, you can send "wink"s, which is a way of saying "I like your profile!" with the subtext "but not enough to take the time to write even one actual sentence to you."
OKC has its own built in "instant message" system, too. It's a very easy way to have a quick flirt with someone who's browsing the website at the same time as you, and is very effective at this, despite being, really, a ghastly javascript hack.
Search
All such sites offer a search facility, enabling you to specify, for example, "women aged 18 to 60 within 100 miles of Portland".
So what makes OKCupid special?
So far, so ordinary. What does OKCupid offer beyond these normal features?
Matching
OKCupid's killer feature is a system called, rather boringly, "matching". They try to match users who would be suited to each other, based on their answers to a collection of special "matching" questions.
All users are encouraged to answer as many of the questions as they have time for. The database currently has several thousand questions in it, but most users seem to answer only a few hundred. Users who answer over 500 can submit their own. The idea of answering hundreds of questions is not as daft as it sounds, since you can just answer a few more whenever you feel like it. It's sort of fun answering them, anyway - it's like a test where you know all the answers.
The questions are multiple-choice. Some of them are very straightforwardly related to dating, e.g. "Could you ever date someone who smokes?" or "Would you date someone with extensive body art?".
Other questions are more about attempting to discern your personality, e.g. "You see a highly attractive naked person of your preferred gender hovering six feet above the sidewalk. Are you more interested in their nakedness or the fact that they are defying gravity?"
As well as your answer to the question, you are also asked how you would like your potential date to answer, and how important their answer is to you, on a scale from "irrelevant" to "mandatory". As such, the system is able to understand that, for example, you like horror movies, but you don't mind if your partner doesn't.
The more of these questions you answer, the more effectively the OKC system is able to match you with potential dates. The system uses the awesome power of MATHS to calculate a "percentage match", which you can then use to sort your potential mates by when you perform a search.
Based on my own experience at least, the system is creepily effective. Going on people I've actually met in person, there is a strong, strong correlation between "girls that I match highly with" and "girls that I fancy". Even just looking at the website, I can see the attractiveness (to me) of people's profiles dropping off as the match percentage goes down.
The Price
OKCupid's other killer feature is its price. It's free. It doesn't cost anything. Most such websites will let you put up a profile for free, and search other people's profiles for free, but then will ask you for money if you actually want to contact the other users. OKCupid lets you use all the features, for free.
OKCupid's appears to be supported by a combination of advertising and donations. Users that donate are able to block adverts and buy themselves a larger mailbox; both relatively minor boons, so it is likely that people are donating out of generosity rather than to purchase these benefits.
The Tests
Distinct from the all-important "matching" questions are the "tests". The tests are user-created and are mostly rather like those magazine quizzes where you answer a load of stupid questions and then it tells you that of all the animals, you are most like a badger.
Some of the tests are quite fun, but, really, they have nothing much to do with finding a partner. I think they only really exist in order to suck people in to the rest of the website.
When you join, it asks you to take the staff-created "OKCupid Test", which assigns you to one of various personality types such as "The Boy Next Door" or "The Peach", or more extreme (and perhaps not entirely serious) examples such as "Genghis Khunt". It's never been clear to me why they seem to assign such importance to this test; it seems largely irrelevant to me. Possibly I just feel this way because it gave me the sappy label of "The Slow Dancer." I can't even dance.
Tips
So, now you know why OKCupid is the website for you. How to make the best of it?
Photos
Put some photos up. Be smiling in the photos. If possible, be outdoors. Be fabulously attractive.
Profile
Have an interesting profile. Try to put something on there that makes your profile different from the others.
Do not, do not use any variation of the phrase "gosh I really hate filling these in." It sounds incredibly negative, plus it's on about 20% of the profiles, so you are at once negative and clichéd. Bad bad bad.
If you're funny, be funny on your profile. If you are arty and dreamy, be arty and dreamy. Express yourself. Let your nature show through - remember, you are trying to find someone who will be interested in you. If you worry that admitting that you are a geek/goth/furry/republican is going to put people off, remember that it will only put off the people you don't want anyway.
If you're reading this, there's a good chance you're a noder here at everything2. This generally means you're into writing. Treat your profile as a writing exercise. Make it an example of excellent writing. In a textual medium, a good writer is very attractive.
Messages
Find people whose profiles you like and send them messages. In your message, try to show that you read their profile, and try to ask questions so that they are encouraged to respond. You can accomplish both of these by asking them about something on their profile.
A poor message: "Hey, you're really cute. Drop me a line."
A better message: "Hey, I see you own a pinball machine, how did you get into pinball?"
A very poor message: "What are your feelings on cybersex?"
In conclusion
Judging by my own experience and that of friends, OKCupid seems to be the most effective dating site out there. The fact that it's free as well is a great bonus. About the only caveat is that the thing is chock-full of geeks. Me, I'm a boy geek, and I like girl geeks, but you might want to look elsewhere if that's not your bag. At the time of writing I'm dating engaged married to a very lovely girl whom I met four months after joining the site, so in my case at least, it worked wonderfully.
Good luck!